Address the wizened elephant in the room
Don't assume every woman you pursue is A-OK with the age gap. Ask how she feels so you can anticipate possible conflicts down the road. She may be new to dating older men, have her own personal reservations, or not even be aware of how old you are. (In which case, keep doing what you're doing, it's totally working.)
There's no need to make a grandiose statement here, but it's totally appropriate to ask how she feels about the age difference. Just get the conversation out of the way and move on.
Treat her as an equal
She may be decades younger than you, but she's still a legal adult (ahem). Understand that she's been paying her taxes, calculating her bills, and making decisions long before she met you. Like any good partner, you'll feel the urge to offer your advice or guidance where you see fit -- but respect that there are times she'll be open to it, and other times when she will not. The latter is NOT the time to dredge up the age gap, or remind her of your years of experience in X/Y/Z.