There are of course always lots of areas for improvement, but in my opinion once you get done the foundation you should be all set, you "made it", and then you can "build" upon the foundation if you need to. That is how I feel. To have a good foundation you have to know some stuff and you have to DO stuff
If you are working on the following you have (IMO) great foundation to "make it":
1. Fundamentals. With great fundamentals your attraction increases multiple fold, girls will be approaching you, and they will be happy to talk to you once you talk to them
2. Abundance mentality. You need to talk to lots of girls, knowledge itself is useless if it is not applied. The more you talk to girls the better and more chances you have, the more confident you will be. The more girls you talk to the better outcome
3. Be ready for rejections, deal with them. One thing is to read about it and another one to experience it. As a Nice Guy/Beta male, you will easily fall in love and you will most likely be rejected several times. You may fall to depression for weeks, months, perhaps even years. You will feel miserable about yourself because she is this cute and hot girl with great personality and amazing looks, there are great vibes between you and her, you think she is your soulmate - and then she will dump you, turn into avoidant person, stop answering your messages and calls, she will act as if she never knew you before. Learn to early cut off girls who have low interest in you, learn not to focus on one girl only, rather focus on abundance mentality BEFORE you get hurt. She can't really hurt you, not unless you allow it
4. Confidence. Confidence is a must, once you have high confidence you can do anything you want. You have "balls" to do many things, to say what you want to the girls, and to get girls to the bed. You don't give a damn about what girls think about you, you just go and talk to them. With true confidence you naturaly appear more dominant and leading, more mature and assertive, more sexy. All very attractive, you are more like a man. No longer you are this shy and hesitant boy, now you look more manly, more like a man who knows exactly what he wants - he wants her, her pussy, and he will never back away from that nor appologize for that. She either has to sleep with him or she has to escape, that is how "hot" it is. There are no friends or orbiting zones, they don't exist
5. Push for sex while getting less emotinal involment (less love) with her. Nice Guys are usually too shy about sex. They have too many feelings for her thus making them unable to pursue sex. She then dumps them because she sees low sexual value in them. Mature guys don't get that easily emotionally involved. They focus more on getting sex rather than on emotional involvement. Because of that they have higher sexual value, after all, sex is what she needs from them
There are many ways and lots of words to describe the same thing, but in essence this is it. Once you understand it and DO IT, you "made it". And the more you DO IT the more you improve and the better you become
Really, what else is there? What else does a guy need?