Good/bad day trading conditions

Some days have good trending moves that pay off well, and some just chop around and take my money. Does anyone out there see certain conditions and just decide not to trade that day?

If so, what are you looking at and do you usually turn out to be right? I have been trading 3AM eastern until 12 noon. So I expect it to start out calm and get more active. Obviously if price is just ticking back and forth between two pips, I am not going to trade, partly because there is no movement, but also because my system will not trigger an entry. But when I get an entry signal, I want to take it because I never know when price is about to make a good run. I would hate to not trade and then a good trending day happens later.

I assume ATR is a good indication, and of course, I always check for economic reports and big news items.

Anyone have any guidelines you use about when to just sit out?

Thanks!!