never have tension, ever. if you are playing fast and your arm starts to tense stop. only play as fast as you can play relaxed. this will lead to faster speed in the long run and also allow you to avoid hurting yourself. repetitive strain syndrome is caused by this.
other than that, try and use all four fingers when playing lead, develope thsi as soon as possible. also try to alternate pick everything. eg up down up down etc.
also with lead pick from the wrist not forarm. the forarm is for changing which string you are picking and the wrist is for striking the string.
i would also sugest when playing lead placing your palm of your picking hand on the strings above the one you are playing. and laying the fingers of the frettin hand on the strings below you are playing. so u are mutting unplayed strings.
ohh also try and play with the tips of your fingers.
cabt think of much else hope this helps.
