Always remember that you must know what you are doing. Get some training in first. The red-cross/St. John's training is fine, but it is only the beginning.
Then what do you expect to happen to you? Do you want a kit for just comfort, every-day stuff or for something bigger, like a car accident? How much time will you have to care for the patient?
I have 3 med-pouches. One for the car, one "delux" portable pouch and one small boo-boo kit.
The one in the car is a much-larger version of the "delux" portable.
The small kit has stuff in it to make every day accidents comfortable.
The Delux kit is what I will depend, have depended on, for major incidents:
(of the top of my head)
6 pairs of Nitrile Gloves (always 1 size larger than what fits)
2 Tqs one ellastic, one static
1 roll 1 inch tape
1 small roll of duct tape
10 small 0.5 ml IV Vials
2 Hemostatic Bandages (1 small, 1 large)
2 Elastic Bandages
1 Asherman Chest Seal
1 Nasal Airway Tube
20 m paracord
1 Wound Closure kit: 1 Scissors, 1 Forcept, 1 Tweezer, 1 Chromic Gut 3-0, 10 3M Steri strips. Note: these are not for Closing Skin, these are four stiching up mafor wounds.
1 Medic Shears
Many Alc. Pads
1 Betadine Ointment tube (the 5% not the common 2%)
1 14 gauge needle with cath.
1 Penknife
1 Led Flashlight
1 Tikka Headlight
6 small satchels of water gel
Safety pins (to pin the tongue to the lip)
1 facemask for mouth isolation during CPR
1 Large zip-lock bag (which can turn into an Ashermans Seal with some duck-tape)
Meds:
1 Vial of Epi + Syringe and needle
10 Atarax (antihestamine)
10 Ciprofloxacin (antibiotic)
10 Nurofen (ibuprofen)
50 Aspirins (as anti-inflematory/painkiller)
3 Vials Bemerol
10 Imodium
1 Aerolin Inhaler
This is the stuff I have in my delux kit (I might have forgotten something).
On the car kit I have also IVs Needles and tubes, as well as 5 Sams Splints.
But the best tool is training!
Note: I am not allowed to use have of the above stuff in the UK. I can use then in the US or in Greece. From experience: you can always find a doctor nearby that is allowed to use the kit!
Edit: I took a pic with a £5 note for refence of the delux kit.