*You need to have an infinite amount of patience
*Don't rush them (attempts to rush them will only result in them moving even slower!)
*Be prepared to do everything at a snail's pace or at the speed of a cyclone.
*Making a gradual transition between activities is important (ie. if they're playing with one thing don't just start packing up and telling them they are now going to do something else.)
*Be prepared to repeat instructions a million times
*Make sure you get down to their level and look at them when you are giving instructions (it works a lot better then yelling, trust me ;))
*Empathy! Understand that the world can be a confusing place for little people who don't always know how to deal with their own emotions. Tantrums are usually the result of frustration rather than them trying to get the better of you.
*You don't need a stack of toys to entertain young kids. Let them follow you and help you with your jobs. Or else send them outside to play in the dirt ;)
*Sleeping does improve as they get older! I know it's hard but try to accept that little kids do not usually sleep for 12 hours straight. These years pass too quickly, so try not to get too stressed about their sleeping!
*Last but not least, be prepared for lots of hugs and unconditional love.