Floating to bluff the turn/river

When is it right to do this? I have done it sometimes playing live because i know the players i play with well, they will normally always c-bet any flop even if they miss so sometimes i float the flop with absolutely nothing to bluff the turn or river because i know they are relatively easy to bluff, but what about online? What tips or advice does anyone have for this play?

Anyone? haha

dry boards that are unlikely to hit openers ranges. normally we want to do this with draws/backdoor draws so we can at least pick up equity..

and we normally do this against habitual cbettors but ones that don't barrel turns often

I think Axx boards are good to float because bettors normally are more honest on these than 8xx boards and bet Q turn with or without a made hand.