Do you place order before time? For example you want to buy Ripple at 15K Satoshi, Its currently at 18K and you feel its gonna go down in a a couple of days and its better to place the order if you are not online to do so at that point.
And also for selling? Do you actually buy an alt, lets say Decred at 0.01 BTC, and you want to sell at least 0.015, would you place order right away so you don't have to keep on looking how is it doing and place the order when it actually goes close to that value?
Is it wise to do that? Especially for really short term trades.
Yes i always doing that especially in Poloniex because their site is getting slow because of the volume of the users so when i buy some altcoins there i immediately place an order to my target price so i don't need to worry and just wait for the price to reach my selling point or target price and after that i earn money without monitoring the price.