I used to trade very intensively, but have now settled for the quiet life... in the past, I did nasdaq and nyse scalping by scanning real time for a whole bunch of features... I also did CNBC plays, you know the "buy the Kernan" kind of thing.... and I also did news plays too, but I found that I couldnt do news plays and real time technical scans at the same time, cos I only have 2 eyes and one head... when I did stocks, 50-75 plays a day was not unusual...
I have kind of toned down my stocks plays and am mainly doing the eminis nowadays, cos you only need to look at one thing... not as hectic as before but just as profitable... I am doing anything from 5 to 20 trades a day on the eminis, depending on the market and my mood... I used to carry multiple positions in my stocks plays, so to compensate for this, I simply upped my size on the eminis, as I am only doing ES... I trade em in a discretionary way, with a bunch of rules that I often follow, but fairly often override too, depending on what my gut is saying... after having had a quiet life on the eminis, I doubt if I can ever go back to playing stocks in the hectic way I played em before...
As for timeframe, the vast majority of my stuff (by a long way) is intraday... September 11 spooked me out, and I think the overnight risk is just way too great if you are playing for direction...