French kissing advice?

Vee
Sooo I've always kinda sucked at French kissing, it's not a super big deal because my boyfriend doesn't mind it, but I'd like to improve.
I understand that u gotta lead into it, but once you actually get going, what should I do with my tongue?
How long do I keep my tongue in his mouth?
What should I be doing with my tongue (I know obviously that u don't shove it down their throat)
Is there anything sexy that y'all do with ur tongue specifically to turn him on? Haha
Any advice is helpful <3 the more details the better!! xo