With any RPG, you're going to have to manage battle. I'm running D&D two Saturdays in a row, and considering last week was uber investigation time (part of the reason why I'm recapping after tomorrow night) I'm going to do battle.
The thing is, in any RPG, it gets complicated. D&D has a lot of rules to manage, but in games with less rules you have to figure out how certain things work together. Even if everyone knows exactly what they're doing in battle, it can get confusing. So how do you keep all of it together?
I'll offer a few of my tips, but I know some of you who've played longer probably have you're own to share. Please do so in the comments! I think anyone can benefit from them.
1) Grids for Initiative. Using them not only to establish turn order but knowing when certain sustained effects go way are great. Graph paper is your best friend.
2) Maps are also great. Even if you don't have a battle map with miniatures, use graph paper to draw out where everything is as the DM. That way, it's easy to say how far something is when a PC asks.
3) No distractions during battle, especially laptops. This is one I'm recently deciding on, but computers are multitasking machines that can delay battle if you're looking up your email.
4) Clarity is something that the DM must convey. Be clear about what is going on, who is hitting whom, and why certain things happen.
5) Planning the next move is something every PC playing should do. Have a good idea what you're going to do when the DM comes to you, don't look up spells and effects at the last minute.