Read "The Logical Trader" by Fisher....the whole book is basically about OR breakouts on various timeframes. He also has the first chapter free online (on his website), google for it. Its a very good book (its not a pure mechanical system though)...i think its more or less something you should use or incorporate into a system you already have.
Another simple OR strategy (that i learned a few years back) is to value the OR's for the daily, weekly, monthly, and yearly....Then to use all those levels as entry/exit/stoploss points. And to value each OR against the others to give you setups....For example, if the Daily OR is higher than the Weekly, but lower than the Monthly you may do something like (1) buy when price is above the daily, with a stop under the daily OR, price target at the monthly; (2) buy any dip below the Daily (but above the weekly) with a stop loss just under the Weekly OR, targets above the Daily, or add to the position with a break above the daily; (3) or short a rally up to the Monthly, with a tight stop above the Monthly OR, target Daily or Weekly, ect...Also, these OR's should be a range, not just one price....for example, I use a 15 minute OR for the Euro (using the London open)....so the OR is usually a range of about 10-15 ticks. I've also noticed that if a lot of OR's are clustered together, your going to get a lot of chop and a small range bound market (market profile whould pretty much classify it as a "value area")....you then usually get a big trending move a few sessions later.
Combining this info with the daily Logical Trader (ACD Levels) you can really weed out the bad trades; meaning you may want to pass on a daily "Aup" setup if the Weekly, monthly, or yearly OR is above the market....you may, instead, look for a "failed "Aup" with stop loss past the larger timeframe OR above the market that you may consider to be resistance.