I read Joe Ross’s chart Scan Newsletter, and he mentioned some considerations when looking/designing setups. I find it to be useful.

• Do I see something that happens frequently, at least as often as often as I want to trade?
• When the event or setup takes place, does it offer me the range of movement I need to be profitable?
• Where would I place my protective stop, and how often would it be hit?
• Is the daily range sufficiently large that I can get the ticks or points I need to make money?
• Is there sufficient volume at this time of day for me to easily be filled?
• Do I get decent fills in this market?
• What kinds of orders can I use to accomplish what I would like from this setup?
• Am I able to find more than one setup in this time frame, and how well can I answer the questions already asked for each setup?