if it is for a girl a ruffle would be nice also. and you don't have to go fancy with the blocks. or with tons of colors. especially if they are not quilty people. they might not want to use it. something simple like a nine patch or four patch is nice. and make sure it is soft and easily crumpled into a little ball. I have two baby quilts one for my son and one for my dd. my dd's I like better because it "feels" softer. and my sons is a little more "stiff" they are both very simple two color quilts. I love them to death. Ds's I made and DD's was a baby shower gift from a lady at church. the quilting doesn't have to be fancy also. a simple SID would be fine. You might want to find out what colors or "theme" the mommy is going with and make something that would work with the room. but this is just my opinion. being a "new" mommy I have two fab quilts from a grandma in law and i don't let the kids have them yet because they are "too detailed" for them to ruin in a year or so. (we are hard on blankets) They are hanging on the walls as art work for now. when they are bigger and wont chew a hole in them or pick them apart then they will get to use them. (they have lots of embroidery on them).
and I would definitely wash them with a softener for babies and baby soap. you can get a small bottle of it from the grocery store. or what I do is cut whatever soap I am using in 1/2 for what is recommended for my kids stuff. (dd is very sensitive to chemicals and other things in fabric). I would also make it close to lap size this way the baby can use it for a long time. hope this helps. you will have lots of fun making the baby blanket. they are always fun to make.