I'm trading 21 markets right now on the h1 TF and get 1 to 2 trades per day. From time to time I get 3 but that is quite rare.
The only way I have found I don't miss anything is to immerse myself in the market 24/7. I have a PC beside my bed and left on all night so that if a market is approaching a key level, I can get wake up and check it.
When I get into my study at 6am I can sit through until 10pm at night without getting too bored as I have a group of other traders to talk too via Skype and MSN plus T2W. Plus I find it interesting examining the price and the way it moves - particularly around key levels - regardless of whether I consider it to be setting up.
I've found I can leave my monitors - as long as I am back for each hour.
I also have a network of people - some through T2W - others that are not - that are looking at setups and alerting me to them or any major market moves so even if I am out and not near a PC, I am usually aware of what is going on. For example, when Gold popped today, I was long but out having an MOT done on my car. I got two texts from different people, already knew the resistance levels, so could just tell one of my mates to log in and get me out (I never use limit orders for targets).
If you want an extra pair of eyes...train some traders.