I don't know what you already have, so I might be telling you about stuff you already have,I'm in the middle of moving my craft room to a new one, so I have been buying Ikea for it, lol. Main purchases so far have been the Expedit cubes, in various sizes, also the desk addition for one of them. You can get twin packs of drawers fro them, little doors, cube boxes etc. Bought three of the Vika tabletops, one to use as my main desk, two for the side walls. Also bought a VIKA Alex drawer unit, for the 'legs' one side of the desk.
In the ( I think) bathroom section, they have a couple of different packs of clear acrylic cosmetic trays for dressing table drawers. Great for pens/glues in your drawers etc. With the home office desks, I found a thick rubber-like drawer divider that you can cut to size for your drawers. Also the SKUBB fabric drawer boxes. In the kitchen section I found some small wooden boxes with two sections- I think they are probably for standing things like kitchen utensils in. Great for pens/brushes/scissors etc.
I agree about measuring before you go- and all their stuff is metric- I still think(and measure) in feet & inches, so remember to convert, lol.It gets a bit stressy trying to convert on the spot! I saw some plastic beaker type things that you can hang from the rails too- I've seen people using them for scissors etc. Have fun choosing all your stuff- I did