Fishermans Friends and pineapple juice, I can attest to that.
I have to yell constantly as part of my job as a street performer.
Another thing that tends to help is not smoking, I smoke socially and it generally means I have some voice difficulty, paticularly with falsetto voices, the following day.

I'm a singer (rock and theatre) and do occasional vocal coaching. 

Here are some tips:
1. Don't clear your throat with closed coughing sounds.  It may loosen phlegm or feel soothing, but it actually irritates your vocal cords.
2. Don't use Chloraseptic or other numbing sprays/lozenges.  They only give you a false sense comfort which allows to cause more damage in the long run.
3. Try Throat Coat or Throat Comfort tea.  Or sprays like Singer's Saving Grace or Vocal-eze.  Similar ingredients in all.  Helps moisten your throat and vocal cords.  Check your local Asian market for a bottle of loquat honey called Pei Pa Koa.  Also has similar ingredients, but in a honey/syrup base.
4. Steam!  Either in the shower or with a vaporizer.
5. Hum.  It's soothing and restful, but keeps you loose.
6. Yes and no to citrus.  Yes when resting, no when close to performance time.  It can dry your mouth and throat.
7. Resonate from other areas of your head.  Voice doesn't just come from your vocal chords.  You resonate from everywhere from the chest up.  It won't affect your character voice if you find the right placement.  It will just relieve the excess strain to your throat.
8. Breath. Often straining occurs because we don't have enough breath support or don't breath enough.
9. Use a neti-pot.  It's odd and it's awkward but it helps.  With your sinuses clear, your head is open to resonate more... again, leaving less work for your vocal cords.

PM me if you have any other vocal issues or questions.

Oh... one more...

DON'T WHISPER!  Whispering means your tightening everything which doesn't help with strain and soreness.

I had the same problem last week while getting over a bad flu.  I had eight performances in one day (each performance being no longer than 20 minutes).  My voice was GONE by the fourth show.  Luckily I had an hour break until the next four consecutive shows.  I drowned my throat with warm tea and lots of honey.  It got me through the rest of my performance....just squeaking by (pun intended).  But my voice was completely gone by the end of the day.  The only thing that I found as a cure was like everyone else said...REST!  I talked as little as possible for the next few days which is REALLY hard if you knew me.  I love to talk. :D  I also felt it was soothing to wrap my neck in a scarf to keep warm.  I don't know if that helped but it felt nice.  I also periodically wrapped my neck with an herbal warming pad.  I think the scent of lavender is always soothing to me...not for everyone.   So, REST....REST...and REST some more.

Now, if your voice is continued to be strained after resting and some time has passed, I suggest you see a doctor.  You could develop nodules on your vocal chords.  That is a very bad thing.  A lot of professional singers develop them.  Julie Andrews experienced this and tragically had surgery that ultimately ruined her singing voice for good.  I am still saddened by this and I am always thinking of this incident when I lose my voice.  It frightens me.  I always try to go for a healthy voice (as my singing coach reminds me).  It's very important to take good care of your voice.  Perhaps thinking of a different voice for your puppet that is less straining is something you should think about.  You know, Elmo didn't have the original voice that he has now.  However, I can't imagine the current voice is a healthy voice choice for the vocal chords...lol.

Hope you feel better soon.

xoxo,
N

One more thing....I don't do voices for my puppets so when I lost my voice, it was just from narrating the story.  So who knows if the real problem is your puppet voice that you are using or if it is just that you are using your voice more than usual.  It could just be like if you don't exercise for awhile but then go out and do a half marathon...although I don't know why someone would do that in the first place....SEE I LOVE TO TALK! lol

Anyways...GOOD LUCK!  Hey you know one other thing that I have found that hurts after a lot of shows...MY THIGHS!  Does this happen to anyone else?  It's probably doing all the actions in my show but I tell everyone now that my new form of exercising is PUPPETRY!

xoxo,
N

7. Resonate from other areas of your head.  Voice doesn't just come from your vocal chords.  You resonate from everywhere from the chest up.  It won't affect your character voice if you find the right placement.  It will just relieve the excess strain to your throat.
8. Breath. Often straining occurs because we don't have enough breath support or don't breath enough.
PM me if you have any other vocal issues or questions.

I think these two can be key and could go a long way in helping folks.  Would you have any suggestions for exercises that would help the common puppeteer develop these abilities. Might be kind of hard to "coach" via internet though.

Unless you have a ventriloquist act, then you should try opening your mouth more.  Try dropping the jaw more or exaggerating vowel forms with a wide smile - these relax the throat and push the resonance further forward to you hard palate, sinus cavities, and forehead.

A great vocalization exercise is to start with a vowel form like "ah".  In front of a mirror, hold that out that "ah" the way you normally would.  Don't worry about pitch, just find a comfortable middle note. Then slowly and deliberately start trying different things with your mouth - lips forward, smiling, through teeth, exaggerated jaw dropping.  Notice how just changing your mouth doesn't necessarily change the vowel, but it will sometimes force the resonance to be stronger at different places.  Now try this with different vowels.  The more you do this, you become aware of your voice and the added versatility you will gain.

Now for breathing... you've all heard about singing from the diaphragm. We learn bad habits.  One of them is breathing from the chest.  Notice babies or even people at rest.  The breathing moves the belly more than chest or shoulders.  This is what you want.  To exercise this, lay down on the floor and breath in a slow and relaxed pace.  Your breathing should automatically move down so that you feel the contractions below the sternum and above the stomach.  Once you are aware of that placement, try breathing that way all the time.

Simple healthy exercises will also further strengthen your breathing.  Jogging, jumping jacks, burpees, situps, crunches, and just about any cardio and core exercise...  It's good for your health, you breathing, lung capacity, and stamina.  Consider adding exercise as part of your performance practice.  10-15mins a day will make a huge difference.

Hi silverK. I have just logged in and saw your post about your voice. My voice packed up completely several years ago. People kept saying that it was probably voice strain from the voices I was using. Others said I probably had nodules on my vocal chords. My local GP kept throwing antibiotics at me, and telling me I had a sore throat. After insisting on a referral to a specialist (which was a 6 month wait)I finally had the problem diagnosed at Royal North Shore Hospital. It turned out to be a little-known disorder called Spasmodic Dysphonia, which means the nerves in the throat spasm when trying to speak.It is worth visiting your doctor to get it checked out. By the way-GP's generally don't know anything about my particular condition-and there is no treatment except Botox injections which help to relax the nerves for about 3 months at a time. I chose not to go down the Botox road, after the specialist said side-effects were unknown, and that the injection can leave you paralysed if the doctor misses the nerve.I simply found ways around using my voice.    Debra Clewer.

Thanks Joel! I think that well really help people out. They are simple ways to start "feeling" what you where saying.

Debra, wow Botox!?  Glad you did not go down that road. I remember seeing a report on a doctor that had helped some people that had lost their voice and could barely whisper if even that. This was something these folks had for years and no one could explain it. Sounds a bit like what your where talking about because the remedy was simply that this doctor learned how to massage and relax the nerves and muscles around the vocal cords. They showed him with one patient that had not been able to do more the croak out a whisper for years and within minuets she was talking normally.  They really did not say if this required on going therapy or if once the "lock" on the voice was released it was all good but it was really an amazing thing to see.

Hi squirrely. I just realised that I gave you the wrong information about our link on the Puppets and Stuff homepage. Our link is on the quick links listing-under school of puppetry. (clewer puppets). If you go to the link, you will see a "more" listing on the right-hand side of the toolbar. Click on it and you will see "freebies". Scroll past the first two pages on starting a kid's club and you will see 4 pages of puppet tips. I hope that this is helpful. Debra Clewer.