More questions

[stand-in-line.livejournal.com]

I thought it was a cute idea when I came across a pattern to make your own underwear.Although Im having an EXTREMELY hard time doing so.It was all good until I went to sew on the elastic.My machine went all dumb,the bobbin thread bunched up and the elastic bunched all up.I was wondering if any of you have ever tried making these and had any helpful ideas? Thanks