I made up a list of the types of sheilahs that many or maybe most people should have, and I will post it shortly. This also includes many things that I have witnessed people doing wrong, which means that they had a sheilah, although they didn’t know it.
Btw, I took a survey on Shabbos amongst the women at the Seudah, and the maskana was that people have sheilahs approximately twice a week (okay so 2 people is not a reliable survey, but that was all I had).
Also, I kept track, and there were at least 6 sheilahs that came up since I posted 4 days ago (not necessarily mine – usually things I saw someone doing wrong because they hadn’t asked, and should have).