The best practice currently is to give people P2SH SegWit addresses when people are paying you, but to support/allow sending to bech32 addresses when you're paying people. bech32 addresses are strictly superior except for issues of backward-compatibility, so eventually everyone will switch over, but it'll probably take a few years; it shouldn't be a format war situation unless someone decides that they hate bech32 and come up with a totally new alternative.
Ah, at last some sound advice to steer this issue in the right direction. I already had some small problems with people using different applications to verify signatures for the different formats. It would be nice if there were trusted software made available to verify signatures for all of these formats.
People are currently using questionable applications to do this and it is causing some confusion.