1) Reraising Preflop
Many midstakes players have a very tight reraising range. They will reraise their big hands, and even though their range is so slim, they still make far more money on these hands than they should be making, given how well defined their hands tend to be in certain spots. These same players are content to just call preflop with certain hands, and even though their decision to call may be +EV, they don't even consider their third option, which is to reraise.
Reraising definitely should be considered. Here is some advice from the HU/SH limit forum to think (but probably not to use preflop): "If you are not sure whether to call or fold, raise!"
It's also good to think about why so many MSNL players do not reraise lightly. One reason is that we're used to playing against SSNL players who are too passive for their own good, who are not raising lightly. It doesn't make sense to open up your reraising range against someone who is only raising JJ+ and AK, and who will not fold to a reraise. When someone raises with A8, 55, and T9, then you can profitably reraise with many more hands.