That's a wide-open question!
There is a lot of advice on TIG welding in s.e.j.w. Superb archive access available through Google at
Look for Ernie Leimkuhler's advice on torch-handling technique and currents. Sttarts of with "amp per thousandth of inch of thickness" then adjustments for... And practice maipulation using pencil and washer (you can left-hand TIG without crashing the tungsten if you have done this exercise first!). Also there: size of tungsten size of filler rod They need to be correct otherwise you will not do well at all.
Th weld pool when aluminium (aluminum!) TIG welding - it's an amazing clean silver liquid appearance, with the glowing tungsten above reflected in it.
Don't know so much about aluminium, but a lot of beginners overheat the liquid metal and run into chronic problmes enough to make a grown man cry, until they learn to control temperature.