developing a rub

[LA Pork Butt]

Big Bob Gibson’s BBQ Book has elaborate guidance for building rubs.

[bbqLuv]

Trying to develop my own rub using Lawry's seasoned salt after watching YouTube videos suggesting Texas Brisket rub is more than just salt and pepper.
Seems to work well with table salt and pepper and a hint of ground garlic. 2-1-1-1/4 ration of table salt, Lawry's seasoned salt, Black pepper, and ground garlic. Really seems to add a little something special.
I noticed that Lawry's seasoned salt settles to the bottom when mixed with Kosher salt and coarse black pepper.
Short of continually shaking the rub mixture, any suggestions?