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 of course, I do that with all of my trades when I do trade altcoins.
This is a good idea cause you are not necessarily going to be online when a certain trade happens and it is probably easier to discipline yourself from selling too low or buying too high. This is like you either get the order filled or you don't, it's as simple as that.
When you have some coins as collateral placing limit orders are also a good idea as you are able to basically stop any further losses to the collateral and sell the collateral before it collapses to a point that it doesn't cover the loan value anymore.
It's a very useful tool to use.