Meet quickly. A week if possible. You don't want to be gassing on to a stranger indefinitely. It's very time consuming
Do not engage imagination. No feelings for anyone you haven't met or barely know
One phone call before meeting, so you know who they are and that you can hold a conversation (once I filtered out an enthusiastic racist this way). Some men love blethering on every night then never meet so don't waste your time on more than one call.
Don't entertain any sex talk in early chats. You're not a prude, don't doubt yourself, you know exactly how shagging works. It's not a good sign if they do this, particularly before meeting. If it's mild, and you suspect it's a misguided attempt at flirting don't banter along, say something good humoured but clear like 'not on a first date, Barry!'. If he realises his mistake, ok. If he persists, put him in the same category as Old Farmer Bumsex and block.
Flakiness or being late early doors has never boded well for me unless a broken down train or something. If it's just 'sorreee running late from work!' I'd probably give them 15 and leave these days.
Generally I think you can tell whether you'll get on as people by the chat, I'm not really in the 'give him a chance' camp if the chat is dry and you're not sure if someone is for you just because they look right 'on paper'. My DP, maybes and good dates have always had interesting and engaging conversation. The 'hi how's work' ones, nothing has ever come of.
Take breaks. It can become tedious
It's ok to say yes to a second date if put on the spot, you don't need to turn someone down to their face (also fine to do so) but put them straight later, don't ghost.
Absolutely not a moral point, do as you please. However, I'd say nothing was ever harmed by waiting a couple of dates for sex when meeting, as strangers online especially. It can be very easy come easy go with no context (pre meeting chat doesn't count for much) and I think there's value in building up the anticipation a bit.
Just keep your standards high and expectations low.