Self sealing bike tubes work great for tiny holes caused by small thorns or other sharps. I have been using them for years with my mountain bike. I change tubes about once per year and can see all the holes that have been filed and sealed.
I used to get a flat tire once per month but since I switched to tubes with sealant I can go 6 months without a flat.
Once thing to note is that they will not repair a major hole like if you hit a nail.
They cost less than $10 each and last me a year. They are available at retailers and online stores. I highly recommend you install them to spend less time fixing flats and more time riding.