How to get a good idle?

[Tom]

Basically i cant get a good idle, eber since i bought the car it idled at like 1100/1200rpm began to annoy me so i set about changing it.
Wound the hot idle screw back and it dropped to 900, lovely i said.
Switched the car off and back on, as soon as i switched it back on the engine was shaking like a shitting dog barely keeping itself going, wound it up a bit then it was fine.
Now i noticed if theres even a hint of electrical load it drops right back and nearly dies.
Also in the mornings the cold idle is really low, but im fairly sure the wax stat is broke because i've adjusted it 2 times and the idle doesnt seem to change.
So basically how do i get a half decent idle consistantly?

[bigcheez2k3]

Sometimes you need to adjust the idle arm on the cable, had to on my old car as when I tried to lower the idle the arm would move far enough over because of the cable.