I am not a Welder by trade, all the TIG I do is on my Bike Build. I did a TAFE (Night School) Course and it was a great starting place.
Like Jon said first get the settings right.
A few things I was shown and all of these things helped me out big time.
You need steady hand, so sit down when you weld were ever possible. I got a a Bar Stool and a mobile Mechanics seat for doing different height jobs.
The TIG prep I was taught, was Mild Steel wiped clean with solvent and then Linished, Ally needs Stainless Brush and Acetone, Stainless as long as it's clean.
Don't be tempted to keep welding with a contaminated Electrode after touching the Job a few times as you do when your getting your eye in.
I found it easier to sharpen all of the Electrodes you got and line them up so you don't have to keep walking back and forward linishing the end as you keep touching the job when you are learning.
Feed/Dip the Stick into the molten pool rather than just melting it with the arc, took me a quite a while to get this one right.
Pete