There are many cool tricks you can implement in your local SEO, like interlinking your Youtube with your GMB and Twitter or interlinking your GMB posts and spamming them with keywords. Another cool trick for example is to add "slogan" property to your Schema code, it is a safe way to add an extra keyword. We always find cool small tricks that help local SEO to rank higher.
If you want to stay on the safe side: Meta T and D with keywords, great ON-Page SEO optimized for LOCAL! I like to get local donation backlinks (donate to your local schools, community, baseball team for a backlink on their "sponsors page") great way to show Google your relevancy, citations are a must for local, get as many as you can, it is essential to keep them consistent with your NAP! make Schema code optimized for local, add every property you can and use as many key-words as possible, ask your clients for reviews, create a system for that like an automatic email which is sent after 2-3 days of the purchase/service.
The rest is obvious ranking factors, backlinks, DA, PA, Page speed ETC.
There is no end to SEO.