First off let me say that your models are a great start. With more practice you'll be producing some great stuff.
You do have to learn to master one of the essentials in painting; mixing your paint with water to get the right consistency. Dripping your brush in paint, then in water is not going to give you the control you need at all. I don't recommend it.
I mix my paints with water in a painter's palette. You can get these at any art shop for very little money. I think I paid like 2 dollars for mine. See the picture.
You'll notice that I have two pots of water. One is for cleaning paint off brushes and the other is water for mixing into the paint. You want to keep your mixing water as clean as possible so to avoid any discoloration of the paint.
Put a glob of paint in one of the bowls on the palette. Cap your paintpot. (keeping it from drying out) Clean your brush. Dip it into the clean water and add one small drop of water to your paint. We're aiming for about a 3:1 mix, but you may prefer a different consistency. For me generally one drop of water is fine. Mix it around with a cheap old brush and paint your model.
You may find that some paints require a few coats on the model. This is ok. You just have to take your time. The results will be great.
This method has a few benefits. !) because you are taking paint and mixing water to it, you use less paint. 2) because you close the lid of your paint pot you are preventing it from drying out. 3) You get a nice smooth coat of paint on your model.