Here's a list of the items I often have in my backpacking first aid kit. Use of the items assumes you have taken a first aid course. It doesn't do much good to have even the most complete kit if you don't know how to use it. The Boy Scouts, the Red Cross and others can give you access to inexpensive, practical courses. Build your kit based on the type of problems you likely would encounter. Review your needs and your kit after each outing. Over time you will have a simple, very usable kit. Here's what is in mine at the moment.

Bandaging

Band-aids, assorted sizes
Gauze sterile pads, assorted sizes
Butterfly bandages/Steri strips
Tape-1" first aid tape
Mole skin
Bandana

Medicine

Ibuprofen/Tylenol/Aspirin
Neosporin cream
Benadryl
Antihistamine
Decongestant
Immodium AD tablets
Peptobismal tablets
Chapstick/Mentholatum
Cough drops
Toothache pain reliever
Sunscreen
Soap/disinfectant
Individual medical needs

Equipment

First Aid Manual
Knife, Razor blade
Needle, Safety pins
Tweezers
Thermometer
Snake bite kit (suction type)
Dental Floss
Towelettes
Matches
Flashlight
Phone call coins

Other Considerations: