Easy!
Select the object/layer you want to “nudge” (-means move…kinda) and with the move tool selected (the black arrow) use your arrow keys to nudge it anywhere you want!
See when you do this look in the history panel! The last thing you did was “nudge”!
i forgot to tell that polygonal lasso tool isn’t the only thing. Depends on the situation. Sometimes it’s better to use the simple rectengular tool or elliptical or whatever that makes marquee :). But in your case (as i saw) it is best to use the polygonal lasso.
it’s me again. I went through a tutorial a bit and there is something that’s really bothering me in the second part of step 2 (crystals). You have to duplicate (ok), change the lightness level (ok), then you have to select the layer and nudge down a bit (ok), and press delete to have a 3d look (?!?). How is that possible because if you press delete while you have the layer selected, the layer will dissapear and not make some 3d effect.