i agree, DO NOT BUY STENCILS.
I just bought some of that camo spray paint that wally-world sells. They have 3 diff. colors. i used all three and they work great.
I did no prep work at all.
I would lightly paint (little spots you missed don't matter at all) the base OD green color. about 1.5ftx2 ft section.
then I made some random vertical stripes with a tan color. (to look like weeds) then I took a little darker brown. to darken he thing up a bit. I made limbs with littler sticks coming off and some more brown lines.
I finished in two days.
GUYS the most imortant part in my book is to not paint blotches or spots. It will look WAY better if you do lines or streaks. It doesn't have to be perfect and I followed to stencils or repeating patterns. I basically always did a section of green. Throw some vertical/random tan grass lines. Then come back and make some trees/ lines with the brown. Touch back up w/ green if you feel the need.
I just went from section to section till I was done. An example of a section could be the back side of the transom or the top or side of a bench seat.
It was not that hard and now our boat looks bad-2-da-bone.
Everyone likes it and it looks better than most I have seen.
This method has made me some $$ by paintin other peoples boats.