A major consideration is the recipient's current watch collection and any expectations they may have for the watch. If they are a new collector just starting out, this is a great opportunity to give them a watch that will really help shape their collection. If this is the case, they have provided you with a very easy way to do this. People just starting out usually need "classics" - some versatile and timeless replica watches that will always have a place in their collection.  
If you're buying a watch for someone who already has an established collection, it can be a little tricky, but not impossible. The fact that you know what they need or what they have been coveting can be a lot of fun. Plus, you know how excited they'll be when they realize you're giving them something they've had for a while. We recommend sticking with the theme of their current collection or filling in the holes in their collection with something completely unique.
This is where things get interesting. If the person you're buying for is into sports or a specific hobby, then there are plenty of great watches made just for them. For the pilot who loves to fly or the jet-setter who travels a lot, consider a GMT-Master watch. For the diver, you can't go wrong with a Rolex Submariner, perhaps with something unique like the new green bezel Ref. 126610LV. 126610LV. For the cousin who always takes you out on a yacht in the summer, the fake Rolex Yacht-Master is an incredible gift. And for the friend who always takes you on epic outdoor adventures, they'll love the Rolex Explorer - the Polar Explorer is perfect for winter holidays, isn't it?
That's arguably the biggest consideration. What we love about watch collecting is that it's not something you store away or take out only on special occasions. A watch is meant to be worn and loved as much as possible - it really doesn't get much use sitting in a drawer. So when you're buying a watch for someone else, the most important thing to consider is their lifestyle and how it will fit into it.