I suggest that we share experience in regards to when it is better to scout a player in order to get a fat one.
As suggested by Kiljaedenas in the Way of the Berserker it is a good idea to scout the players at the day or Terror. While you might catch one in the middle of the boost you might also get a nasty surprise, which you cannot beat. I think that this is a very good strategy when you are maxing out the primary offence. However, after getting to HQ 20 and maxing out all LCs and 2-3 sets of troops (which you can have at XP 48-50) this strategy might need some adjustments.
I always scout all new bases as soon as I open the game. Before maxing out several of my troops (for HQ 20) that allowed me to replace difficult or resourceless players as fast as possible. I noticed that quite often the players appear on my map somewhere between 15 minutes to over two hours after they boosted for the attack. And even if they don't boost they are often online if I attempt to attack straight away.
So my guess is that it is better off to scout the player somewhere between half an hour to an hour after he/she appears on the map. If we scout too eary then the palyer has not accumulated enough resources yet. And if we scount too late, then the player has already spent the resources.