Alexander Elder recommends (but advises you to find whatever works best for you): 22 bars for the daily chart and 26 bars for the weekly chart. He recommends use of % based bands (not Bollinger) and MACD 12,26,9 too.
Quote from Bitstream:
Bollinger bands are useless imo: u can see possible entry/exit but only at times and on insight (after the fact).
I use 20EMA, 50EMA and 100EMA: good for any time frame.
MACDs also is pretty reliable.