-the canvas is wrinkled from being folded, some of those wrinkles won't paint out, you may want to iron it (or save some effort and throw it in the dryer for a spin)
-use the cheap paint for glueing on the canvas, it took me 4 gallons just to get the roof and one side canvased, the hatch is not canvased now (in one epic downpour last summer the rain found every tiny hole flooding the galley, if the hatch had been covered it wouldn't have leaked so much)
- edges, lumps, bumps screw holes, knot holes, fill and sand, any imperfections will jump out when it is painted. (use a router to put rounded edges if you want them)
-prime the wood( primer is cheaper than paint)
-cut the canvas side panels to rough shape leave a good margin around the edges
-cut the roof panel slightly oversize
-lay the canvas ,inside up, on some clean surface you don't mind getting paint on (do the sides first, use the roof as the paint area, or lay plastic drop cloth over plywood) and roll on the paint nice and thick ( I used 8 oz canvas and it soaked up tons of paint)
-roll a thick layer of paint on the part being canvased
-lay the wet painted canvas, paint side down, onto the area, roll out any bubbles and wrinkles with a paint filled roller, keep rolling on paint until the canvas stops soaking it up. (watch for drips on the edges)


-make sure any edges for hatches etc. are painted to hold them, I found cutting my round windows worked better after the paint dried, for square openings like my door cutting the canvas while wet and gluing it to the inside of the door frame worked well. (I've reworked my doors three times since, I wish I'd had them right the first time to protect the inside of the door rabbet)
- trim, vent covers, installed while the paint is wet will glue themselves in and if you try to remove them they will take some paint

-after the paint dries the canvas will look dry if it soaks up like mine did, I let it dry and then painted in a top layer of expensive gloss porch and floor paint (kind of a waste, I now like Glidden better than the expensive Behr paint after more than one paint failure on my mouseboats using Behr)
-I like the textured look the canvas gives but the cheap canvas drop cloth has lots of pills and strings, get better quality cloth if that bothers you. (bed sheets material, more expensive by the yard, however much less paint=less weight, and the same strength to the paint, thinner fabric will not hide as many surface defects

-bugs are attracted to fresh paint

-make sure you know exactly where the door hinges attach (this got a lot of paint on my gloves and screw gun that shouldn't have


-rain will leave grooves in fresh paint


-pinking shears will make your edges look much more finished
hope this helps!