Which camera and stabilizer are you currently using? I've made shots using something as small as a Canon Rebel DSLR with a very light zoom lens on a Steadicam Merlin which can't be distinguished from shots made on a much larger Steadicam Rig. More weight always helps of course, and a vest/arm mounted system helps significantly to reduce the chance of footsteps showing up in your shots. The horizon thing takes time unless you're talking about those electronic brush-less motor gimbal stabilizers. I've even had great luck with an extremely bare minimum weight rig (Steadicam Smoothee) using an iPhone. Hope this helps!