Girth is more important than length but keep in mind too that a woman's canal varies in depth just like a man's member varies in length. There IS such a thing as too long. Too long can be pokey and uncomfortable for the woman. So physically the ideal is to have good physiological compatibility. That means you are sized such and she is sized such that y'all can enjoy each other without you having to worry about going "too hard" or hurting her by bottoming out at her cervix.
In my 20s I had a 5 year LTR with a great guy who had plenty of girth and length, but he was actually a little too long for me and we had to be a little careful in certain positions or it was pokey.
Communication is key. Some women are completely bashful about telling you what they like or what gets them satisfied, but encourage them to let you know in a non-judgemental way. There is a certain vulnerability and exposure to being naked with another human being. Essentially you are entrusting another person with your unvarnished physical being. Women get worried about whether or not a man sees all the physical flaws that she sees, although a man probably is simply enjoying the presence of a naked woman. Just like men get worried about their member and it's width, size, curvature, etc. Communicate gently what you enjoy. Help her please you. If she isn't an expert at the blow job help her by encouraging her to do what you prefer.
Also keep in mind that what most turns a woman on initially is your desire for her. Pay attention to her while you are in bed together. Look at her, compliment her. Be present in the moment (that means do not be so busy trying to hold back your climax that you fixate in the pattern in the drywall or an algebra equation or some other unrelated thing.) Let yourself enjoy her and allow yourself to climax. If you think you didn't last long enough tell her that your desire FOR HER got the best of you, and know that you'll have another go after you recover for a little bit.
What turns a woman on most as you become more established lovers is your KNOWLEDGE of HER in addition to your desire for her. And over time a comfort level and an emotional intimacy should begin to get established as well as physical intimacy. As that intimacy gets established things have the potential to get really awesome in bed.
Men who can create the illusion of this sort of emotional closeness and intimacy on a first encounter are the Casanovas running around. It is very difficult to achieve great lover status on a first encounter. Unless you have already made the investment into knowing something about the woman emotionally, you have already built some sort of connection. You've created sexual tension, which women love.
Men may think "Sheesh, can we get to the fvcking already?" but women aren't wired that way. Women need the get warmed up to the idea. Women need that emotional engagement. If you can slow it down and enjoy the seductive process (Art of Seduction by Robert Greene spends pages and pages on this concept) then you will build sexual tension and also enhance your own anticipation of the physical conquest.
Don't be in such a big fat hurry!!
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