Also, stop kicking as soon as you're negative. It seems that it takes longer to reach the bottom but you'll increase your dive time.
Be careful and enjoy.
If you take a free dive course they will teach you to be positive to 30 feet. From 30-60 or so, you're converting from neutral to negative and beyond that, especially with your thick wetsuits, you're going to sink fast.
But, if you're hunting at 20 feet, you don't want to positive to 2 atmospheres...or 33 feet. You'd rather be maybe to only 10 feet so you can lay on the bottom without fighting it.
Exact proper weighting is hard to strictly adhere to if you're diving at different depths during the course of the day....like Marco going over 100 feet. 
But positive buoyancy is very important near the surface so if you DO black out...you won't sink right back down.
But Marco makes a very good point. And I have to take a bit of time to get into that mode of relaxation. "Relax your eyelids" was advice given to me. And as I pass 30 feet or so and become neutral to negative I try to relax the grip on my gun, my neck muscles, legs....just drift down and angle my body to land where I want to go. Once on the bottom, even holding my head up burns O2.
Some days I'm just more into that state. I hit it yesterday and ironically, I didn't get one fish. But I was having a great time exploring new spots and doing some good dives....for an old fart. 
