As a teacher I've often come across the people who want a 'magic fix' as suggested by Shimrod.

The only way to be any good at music, whether singing or playing, is by hard work - unless you are dead lucky and naturally talented.

The place to do your practice is in private, and only to inflict yourself on your poor, unsuspecting public once you are satisfied you are up to the job.

If, as was also mentioned, you are in a small, select group of friends, it may then be acceptable to do your practicing in front of such an audience.

If you cannot judge your quality of performance from the reaction of others, then you aren't ready - or just too thick skinned!

I do wonder about people who seem to think singarounds and the like are appropriate places for the talentless to insult the intelligence of others. It's all very well saying people have to learn somewhere - but this thread is really about those who will never learn!

As a competent singer and musician I gain my pleasure from knowing that the audience enjoyed what I did. I'm puzzled, therefore, by what pleasure an incompetent performer must be gaining...

Anything I try on an audience that doesn't get the reaction I hoped for isn't kept in my repertoire - but that happens very rarely, because I've the experience to know what audiences like.
Karaoke bars combine two of the nation's greatest evils:
people who shouldn't drink with people who shouldn't sing...