Gertrude, I'm going to slap your legs for that one!
If you are in a normal powered aircraft such as a Cessna Spamcan and you find you need to s-turn or slip it in, then go around and do it again properly.
If you have had an engine failure and have no choice, then do whatever you need to get in. Read the flight manual as to whether sideslips are prohibited (For those who assume that Cessna 172's are prohibited, then RTFM. Not all 172's are.) and then go and practise the damn things at altitude until you can do it without screwing up.
It isn't hard and might just get you out of trouble one day.
S-turns are fine, but side slips at least keep you pointing in the right direction.
Am I right in thinking that people haven't been taught how to side slip whilst training for their PPL? If so, I'm going to shake my head in disbelief.