Programming Problems

_Cheyanne_

Hello, I have been off the wagon for a while, but have returned to the world of health once again (Thank god). I recently picked up Rippetoe's beginner lifting program (again). I'm on my 4th week, and I think I've gotten rid of the initial quick gains; I've started focusing more on the power output and bar speed than upping the weights. At the moment the schedule looks like this:

Day 1: Squats
Press
Deadlift

Day 2: Squats
Bench
Power Clean

I'm supposed to start adding assistance now apparently. My problem is that I haven't had much of a change aesthetically. My goal was/is to gain a base of strength first, and then move towards things that change my aesthetics. But.... How do I do this?! Rippetoe's program is strictly for strength gains, so how do I implement exercises that give me the changes I want without overdoing it? I could also be baffled because I expected slight appearance changes after just the main lifts. Do I even need to add more? My brain says this takes time. But I'm also irritated with my progress. I also want to start some kettle bell exercises, or something that can involve or create the "twisting" motion. I didn't plan on following this program to a T, in fact, I'm more interested in learning how to program my own stuff. Can anyone give me some advice? Full body movements are important. Strength is important. But having a nice behind is important, too.