Firstly you need some basic tools and you may already carry these with you. I'd start with the most essential things that do 90% of the tying work. These are:
- A needle
- A vice of sorts
- A cake of coblers wax
- A bobbin holder (not essential but earns its keep)
Apart from the Vice these are items I carry in my sewing kit. I'd use hemostats as a vice, these are cheap and weigh very little. The benefit of having hemostats is that they are extremely useful in their own right.
So setting up first you will need to prepare your thread by rubbing wax on to it, simple enough, I find I can tie a size 12 hook with about 2.5' waxed. The wax makes it last longer. Then put your hook into the hemostats and lash it tightly to a log with whatever cordage you choose or have available. All pretty easy so far. Now comes the hard bit, learning to tie, and this requires a bit of practice and patience...... Infact I think it is a post in its own right.