Make a plan,stick to it,and do it consistently.(The plan has to make sense and have merit from the start.)
Specialist in my opinion make more and are much more sought after than generalists.
I focus on a few niches that I work to dominate everyday.When you start closing volume with a particular niche you will start getting REALLY GOOD at it.You will start reaching levels generalists can't touch.
So if you have 4 sales in a few months 1 is land,1 is retail,1 is lake homes etc. then you will have gained a little knowledge in each.
However if you chose one and really marketed and focused on it you will have all 4 transactions in say Lake Front homes.You will start developing a rep and referral base to dominate.
The NUMBER ONE problem with agents is the "NEXT BEST THING SYNDROME".
They start doing something and it starts working and gaining traction.Then when a new shiny object comes a long they dump everything giving them results and start over again.
If you have something successful you stick with it and add the other strategies along the way.You build niches that ebb and flow with the markets.Maybe sales are hot now but in a few years land is strong.You have to look at the data and see what is selling and what is not.
Taking listings means nothing if they do not price correctly and have a product in demand.