The best way I have found to improve is a rather simple one,
keep making mistakes and learning from them., and not repeating them.
The more figures you paint, the better you will become.
The easier it will be to mix your own colors, you just rotate the shelf, tossing out the old as the
improved one take over.
Wish I could help you with the 1/72 scale, but not my scale, but I would
think it would be the same as in 1/35.
take your time, and assemble them, and place around the wheels.
I usually paint my tracks first, if they are link and length, or just links,
I do sections at a time, place them on the model, let that section dry, (at least over night)
and then move on to another section.
A piece of advice given to me years ago by Shep Paine,
(back in the days of real teeth and hair)
"Dave, remember, they all do not turn out,
and remember they all are not going to be masterpieces,
just remeber, we all started out as newcomers once.!!!!"
Wecome to the site, and remember it's a hobby,
have fun and enjoy it.