Upload thoroughly optimised photos
Photos always get plenty of views, so make them relevant and interesting, but be sure they are optimised. This is an advanced technique that adds a little more juice to your GMB page.
Add some original text in the description
Many people leave this out and it leaves you missing a powerful part of your GMB that can also hold anchor text backlinks to your web pages.
Expand your reach to areas within a radius
Not many people have used this strategy because they don't know how to do it, but there are ways of making your GMB page appear in the three pack in surrounding suburbs/villages etc.