Hi guys!

I have so much trouble with drybrushing, which is not a good problem to have when building armor.

Every time I try I get one of two results. Either I wipe too much paint off on wy paper towel and get nothing on the model, or don't wipe off enough and get streaks. Any tips?

I assume you use a proper soft wide brush?

Anyway, having too little on the brush isn't that bad, too much is bad.

What I do is use some kitchen-tissue, that has some embossed pattern. I wipe the brush on that. Once the paint starts to only show on the edges of the pattern, you know it's properly loaded.

Good dry brushing is an exercise in patience. You can't have too little as the best effect is built up over a succession of coats. This lets you control the highlighting and can even give an effect of paint wear on certain surfaces. Like Herbert, I use a textured tissue or paper towel to check the loading of the brush. When I feel comfortable with it I begin. I may even use the back of my hand to see if its too wet. If you can see the texture of your skin then you know you are on the right track. The first coat should almost be invisible. As you build up layers you'll start to see the highlighted areas stand out. This may be in three coats or it may be in 10. All depends on how you like to work. I usually highlight with different colors, using a darker highlight for the initial drybrushed coatings and then moving to lighter colors as I progress. This makes for some nice depth and some really nice highlights.
Too much or too heavy a coat, especially with acrylics will look grainy. While this has a definate plus in some instances, i don't like it on armor or metalic surfaces.
Using oils can be easier for some and can provide some smooth transitional tones and highlights on surfaces and edges. A nice technique that I've been playing with and really getting some nice results is a reverse highlighting. i.e. doing a base coat of desert yellow or white and then drybrushing with oils or acrylics, dark grey. This looks like paint wear and if done properly and patiently can make for that good field worn paint or white wash look.
Its always better to start conservatively and work up than to start with too heavy a dry brushing and have it look cartoonish or overdone.

Thanks, guys.

This is my second tank, and since the first didn't turn out as well as I had hoped because of this problem, I don't want to make the same mistake.

I use a 1/4" red sable brush, if that makes any difference.