designer/printer/installer/production, I do pretty much everything for the sign/wrap portion of the shop
Kinda guessed that. Well, to be blunt I wouldn't hire you for minimum wage as a designer on my shop. The designs you have posted up have been horribly out of the same league of your current logo, and your current logo could REALLY use a new look. With your current grasp of design, you simply aren't going to hit it.
This is where you hire a designer to create a complete identity for your shop, and as the in house designer, thoroughly examine what they produce. I might suggest Dan Antonelli(blows me and most on here away)? He does great work and works with a lot of sign shops. Have him create a logo and identity, give you some guidelines on how to use it, and let 'er roll.
Then if I could offer a suggestion for the future, if you'd like to continue on the path of designing, get some good books. Mastering layout, Antonelli's logo books, or I like Identity Crisis by Jeff Fisher. Then, start breaking down good logo's, layouts you see.... and keep designing. Something fun and good for creativity is in the morning, before you start work. Set yourself a time limit, sit down with a cup of coffee and design a logo for a fictional business. Give yourself a fake job, no boundaries, and create something cool, fun, attractive or sleek for them, but within the time limits. I find it very stimulating!
Then just keep at it and stuff will slowly start turning around and looking better, and better, and better.
My $0.02 for the day.