Originally Posted by jathu
Make sure you use your wrists whilst bowling to get extra pace and you should always bowl across to the right hander.
I don't really understand this. I think what you're saying is that a left arm bowler should always try and bowl over the wicket angling the ball across the right hander which, as a batsman, is exactly what you want a left armer to be doing. Unless there is swing (which I am assuming there isn't as the original point was a 'normal ball'), the bowler is completely taking out the lbw.
IMO, a left arm seamer should be trying to mix it up if he is unable to bowl a delivery that swings much. That means trying coming around the wicket, or delivering from different points on the crease. Not doing it every other delivery, but certainly throwing it in for an over or two in a 4-6 over spell.
As far as actual variation deliveries goes, its pretty much the same as a right arm bowler, although an inswinger is arguably the most useful tool. However, an easy variation to bring in is the off-cutter slower ball, its amazing how decieving running your fingers down the ball can make a delivery.