I previously described this setup in the post below. I would ordinarily do it in SPY, but I have SPY iron condor setups on and IWM is a good instrument to play with this strategy, since it is the index ETF with the smallest value among SPY, IWM, QQQ, and DIA.
Here's the setup:
Aug 19th 97 long call
Feb 19th 115 short call
Entire Package: 16.83 debit (1683/contract)
Notes: (1) Look to take the setup off in its entirety if profit reaches 50% of the credit received for the short call. In this case, the credit received was 2.77, so look to take it off when profit reaches $138 or so. (2) You can roll the short call out for additional credit should that be profitable, keeping the long call in place, but I generally prefer not letting the long call get to less than 150 days out or so to ensure that the vast majority of its value remains intrinsic.