How to build my checks!?

Hi, I’ve been serving for a few years and I would like to think I’m pretty good at it! I make little to no mistakes, and I almost always get 20% . I recently started at a restaurant where all the servers pool tips (which I’m totally ok with!) and I’m noticing that the other servers are able to sell way more than I am, making me feel a little guilty for bringing less to the pool. If we weren’t pooling, I’d be okay with my numbers at the end of the night, but the other servers are pulling in so much more!! Does anyone have any suggestions to how I could be building my checks for more $$$? I try to sell extra dishes but my guests rarely take me up on it. How can I convince people to order a second drink or an extra side? Any advice would be greatly appreciated :)