|Depending on the fabric, thread available, and the abilities of the sewing machine, traditional buttonholes can lend a real "made at home" look. I have taken to making bound buttonholes, which look like miniature welted pockets. Because they are made of the same fabric as the garment, bound buttonholes match perfectly. I especially like them on jackets because they are sturdier than thread buttonholes.
There is a Dritz Bound Buttonhole Maker that makes nice, thin bound buttonholes. It may be discontinued but is occasionally available on E-Bay. I got mine from a clearance bin at a fabric store--the faded packaging suggests it was ancient.
If you can't find one of these tools, you can still sew bound buttonholes. There are instructions in many sewing books, as well as online.
Don't worry about messing up. Practice on scraps and then, when you've got the hang of it, begin on the front of the jacket before you have stitched it to anything else. That way, if you do mess up, you only have to cut one more front. The buttonholes go on the right side for women/girls and on the left for men/boys.
For each buttonhole, my bound buttonhole maker calls for a 2.5" square of fabric cut on the straight grain. I like my welts on the bias because they have better recovery and there is no need to match stripes or plaids that way. So I cut my 2.5" squares on the bias. For short buttonholes, the 2.5" gets trimmed shorter after the buttonholes are sewn.
The length of the buttonhole depends on the size of the button. The button needs to be able to move in and out of the buttonhole easily, but not sloppily. Use a piece of thread to measure around the widest part of the button and make the buttonhole at least half that width (a tad longer if the fabric is very thick). Sew a test buttonhole on a scrap of the same fabric to test the length.
You don't always have to use the same fabric as the jacket: I have seen contrasting bound buttonholes made of velvet and boy, did they look exquisite.