I do not have a grid wall in my trailer dressing room, but I have maximized my wall space storage with collapsible tack hooks, utility hooks and a couple of over the door coat hooks. The dressing room has indents by the nose walls, and along the upper ceiling edges to hang hooks. These hooks have never slid/fallen once hung, but the location is easily changed.
A trip to Walmart kitchen section found some stackable wire baskets to hang on various hooks. Lowes/ Home Depot has hanging wire shelves that may fit in trailer dressing room. A plastic stacking three drawer bin set holds people drawer; horse medical drawer and finally tool kit drawer. Lowes provided the heavy duty rolling tool box that makes an awesome trailer tack box/step stool and chair.
You may want to use your trailer for a bit to get an idea of your flow of movement in and out of your dressing room so that you are sure of the location of your grid wall. You will want to know what you will routinely grab first and must be close by, and what can go higher or to the back wall.
If you have places that can take a hook of some kind, investing in a few with some baskets will help you decide how and where you will find permanent storage.
Wishing you many happy miles with your new trailer.