TBH this is something I need to work on right now as it is the part of my game lacking the most. I tend to forget odds most of the time. This is generally because I know where I stand in most situations. But then the weird situation happens and I'm just not used to employing odds etc, usually I goof up and make the wrong move as I later figure out.
Nice little tip when calculating your equity is to take your outs and double them per street. Like flush draw on the flop, supposing you have the full 9 outs, simply double to 18% equity for the turn, and double again to 36% for the turn + river. Now this isn't exact, you may be off by 2-3% at most, but as you become more familiar with certain situations you will know where to apply a slight -/+ % of equity.
I'd be interested to know if anyone else uses this method, or if there is a more viable way to work out purely mathematical decisions on the spot.