i dont find portraits that hard to do, thin wood is a bit tricky imo, the blade run through it like a knife through butter, and its easier to brake, i use thin and thicker wood (one inch, if i get that right, iam dutch so not used to inches, i use 1cm thick) the thicker wood (one inch? 1cm) is imo easier.
The backer board i use black thick paper, dont know the english word for it, but its used behind pictures when framing, when i dont have that paper i use a thin piece of mdf and paint it black or some other color you prefer.
there are some easier patterns available, for you to try. Look at Steve Goods website or on this one.
hope i was of some help.
Good luck