Hardware and Configuration Tips for WOW Healers
Let's look at an example to see why that might be the case. Say that you want to cast as many instant heals as you can in a 10 second period. Although they are described as being "instant", they actually trigger a global cooldown when you can't cast any other spell. The global cooldown is between 1 and 1.5 seconds depending on your haste and certain spells that have shorter global cooldowns. So, lets say it is 1 second in this scenario just for simplicity. The absolute most heals you can cast in 10 seconds is then 10. To do that, you need to complete all the steps required to cast a heal in 1 second. Deciding who you want to heal can take up a large share of that time and that is unavoidable. So, you need to handle whatever clicking and mouse moving steps are required to cast the heal in only a fraction of a second. Just to make up numbers, lets say that identifying a player in need of healing takes 0.5 seconds. That leaves you 0.5 seconds to complete all the mechanical steps before you start eating into your healing efficiency.
If your process for casting a heal is that you click to select the player that you would like to heal, move your mouse down to the button for the heal, click that button, then move your mouse back up to the raid frame, you're trying to cram an awful lot of things into that half a second and you aren't likely to make it. If it takes you one full second instead, then in 10 seconds, you'll only complete 6 or 7 heals instead of 10. On top of that, performing those steps doesn't really just take time, it takes concentration. You need to be focused on looking around for the right button, tracking where your mouse is moving and so on and as anybody who has ever died from standing in the fire like an idiot knows, freeing up even a few cycles of concentration here and there can make a huge difference. If you're bogged down with managing all these mechanical processes, that eats up an awful lot of your mental capacity.
The good news is, there are some straightforward configurations you can make that greatly reduce the number and complexity of the steps you need to perform during the global cooldown window.
Key binding
The worst time-suck in the process of healing is moving your mouse away from the raid frame, finding the button for the spell you want to cast, clicking it, and moving your mouse back up. If you're doing that, you can make massive gains just by taking the simple step of binding the spells you cast most often to keys. It can take a little while to get used to and at first you'll likely be casting the wrong spell from time to time or finding that you have to stop and think to remember which spell is which key. But, that passes and once you're used to your keybindings, they become second nature and your hand is pressing the right key without you even consciously thinking about it.Different people have different ideas about how best to configure your keybindings. It really depends on your class and how your keyboard is set up. Generally speaking, however, the keys you bind should be right around the keys you use to move your character around. For me, that is actually on the number pad, but for most people, it is around the "WASD" keys. The problem is that you can only really quickly reach so many keys without having to move your wrist, which you don't want to have to do. You can get around that limitation by using combinations like "shift + x" to double up.
Mouse binding
People differ on this, but personally, I find binding spells to mouse buttons to be more intuitive and faster than keyboard keys. Even with the most basic mouse, you can bind clicking the scroll wheel and potentially even the right button to spells. You can always switch the standard right-click functions over to something like shift-right-click, since you don't use them too often. But, where this strategy really starts to work is when you get a proper MMO mouse. There are a number of MMO mice to choose from, but the one I use and strongly recommend is the Razer Naga, which is basically designed for WOW. The Naga has 12 additional buttons on the left side where your thumb goes. There are a number of mice that do that, but IMO, the Naga has the best feel and did the nicest job of varying the shapes and angles of the buttons so that your thumb always knows which button it is on by feel.Mouseover
You can cut another step out by using mouseover macros, so that you do not need to click your target at all, you just hover the mouse over them. Alternately, you can use an add-on like Clique to achieve the same thing. I personally like Clique better for simple bindings and only use macros if I'm trying to do something fancy, like using a trinket at the same time as I cast. This approach works well even if you're using keybindings, but where it really shines is when you've bound buttons on your mouse because then you intuitively feel like you're "clicking" on your target to cast the spell, just with a different mouse button.One advantage of the mouseover approach is that you can keep something targeted throughout the encounter. I often have the boss targeted so that I can see who he is attacking, so I don't end up wasting heals on the tank that just rotated out. Alternately, you can keep the main tank targeted so that you can bind keys to casting your most commonly used spells on your target rather than your mouseover, and then you have a nice default action when you don't see anything else that needs doing- heal the tank. You can also use your focus rather than your target for this however. I generally target the boss and focus the main tank and just kind of idly cast cheap heals on the focused tank while I'm trying to decide what to do next.