I don't have twins, but I do have three kids under five. I'm pregnant again, and actually nervous that we may be having twins.you will probably need two of each of these items:bath tubs/seats if you want to bathe them at the same time. Angelcare makes a nice bath seat that will allow you to bathe both babies in the tub at the same time. If you want to bathe them individually while they are little, you can get a really cool flower insert for your kitchen sink. I can't remember who makes it, but you can google it.two bouncy chairs. Very helpful if you will be bottle feeding. If you'll be breast feeding, you can just have one bouncy chair and one swing.two jungle gyms, or one large play mat for tummy time. If you do one large mat, there are some cute stand up mirrors from skip hop that will help keep your babies entertained.you should have two boppy pillows. If you breast feed, you'll want one, and they're great for propping up your baby next to you on the couch, for tummy time, etc.two car seats, of course, and a double stroller. Two cribs, two bassinets, if you'll be using them.later on you'll need two high chairs, and maybe two jumpers/exersaucers.as far as other things go, you'll need double the amount of clothes (I like to have about two weeks worth of jammies and outfits, at least while they're little and spitting up a lot.) double the blankets (2-4 of varying thicknesses for each one).check out The Honest Company for diapers, wipes, bath products, etc. They are organic, affordable, and really great. I've been using them since my last baby was born and I absolutely love their stuff.