Badgers are decent airbrushes. I have not used one in a while, but most of their older models were like plain Chevy\'s - no frills, get the job done, but the ride might not be the smoothest.
Paint should be thinned like milk. I use liquitex or createx airbrush media when I am reducing. Vellajo makes an airbrush media as well, but I can get Createx in quarts (liters).
By the nature of the application, airbrush tends to be semi transparent. If you are laying down an opaque layer other than black (or some very dark color), then you are doing something wrong. Apply several layers building up the color as you go. It is always easier to add.
The 150 is a bottom feed dual action gun. Paint come from a bottle attached to the bottom. This means that a minimum amount of pressure is required to vaccuume up the paint into the gun (usually about 5 to 7 psi).
Dual action means you will push down on the trigger to get air. Pull back to get paint. The further you pull back, the more paint you get. Then (important) let your finger go foward to stop the paint leaving the air on. If you just release your finger, you will have tip dry problems at best an run the risk of damaging your cone (the little tapered area that the needle stops in).
When you are done - not a couple of hours later, not the next day. Flush the gun, take the tip and cone out and flush them. I use a small interdental brush in the cones. Slide the needle out and flush the gun and make sure the needle is clean. Any bit of paint left in the gun will become a blockage later. Reassemble the cone and tip. Slide needle in until it touches the cone. This is where it should operate. For storage, I pull the needle back about an eigth inch.
Order a set of air-brushes (like little pipe cleaners and bottle brushes) and a spare needle and cone. You will damage the tip of your needle by hitting a mini or airboard. We call it tip crash and everyone does it. Generally, you will leave a nice scratch in the mini and bend the tip of the needle. Cry, learn and move on.
A great set of drills to work with your airbrush: Get a set of the paper towels that have the dots on them about a half inch apart or so - spacing is not real critical, but having a dot pattern is. Shoot from one dot and stop at the next dot. Horizontal left to right on one row, then right to left on the next. Mast that, then do vertical, top to bottom then bottom to top.
How thin should the paint be(I\'m using VMC paints), is it wise to use VMC Glaze Medium to thin the paint, so there is no loss on the pigment, how much distance should I keep? Is this a good airbrush btw, any tips are welcome 
