yeah it depends on the situation.. sometimes a drop might sit there for 15mins and then bounce back up.. so on a one hour candle you cant tell that it was a thin book or an actual base that took 15-20 mins to bounce.. So you have to look deeper than 1hour candles if you want to make the call.. but if its a really long tail, then I would think you mark your base a little closer to the body.. if its a short tail than you can just mark the bottom..