Beds with just a headboard always look comfortable, and they are cheaper than the headboard/footboard set. This one is courtesy of Pottery Barn. The seagrass gives it a good texture. If you want a footboard alternative then you can put a bench on the end.
I like this comforter from Target. It is a fun color but not too bright and it compliments the brown really well. I wouldn't go with the matching sheet set, though. Too geometric. I would stick with solids.
If you are looking for accessories, lamps are an easy way to go, especially in a fun color like this one from Pier 1.I would end with sheer drapes (floor-length), because I like how much light they let in.
If you are painting, I have ideas for that too.
Of course, these are just suggestions.