Low key blow job tip?

Clareth
So my bf and I been together for almost 5 months, I've told him I'm not very experienced with bjs lol just so he won't think I've been around lol. 
 I want to give him one and Im quite experienced with it but I don't want him to know How experienced I am lol 
Anyone got tips so I won't give it away ? Lol 
& when do u think it's a good time to show him my skills without leaving him thinking I've sucked to much dick before him lol