It's a nightmare! And I am the neutrals queen, but I still suffer months of angst in the run-up to each room, even though I've been a devotee of off-white for about 15 years! And don't get me started on buying matchpots...
This months edition of one of the interiors mags (Home and Gardens I think?)has a really useful supplement from Farrow and Ball with lots of info on how to mix neutrals, get the balance right, add interest and depth to the scheme using texture rather than colour, and how to use a small amount of accent colour to stop it becoming bland. A really useful little booklet and well worth the cost of the magazine! Very few off-whites, creams and beiges are truly neutral and many will show up as yellow, green, grey, pinky, or brown. Start by analysing the natural and artificial light in your room, and consider the aspect. For example, a north facing room can make things look greener, so opt for a slightly warmer shade than you would otherwise use. The Paint and Paper Library is really good because they have four or five depths of the same colour so you can pick 2 or 3 and be sure that they will work together.
Having said that, in my experience you can sometimes try too hard to match things perfectly and the result is a bit boring because everything is too similar. Hence I have just painted my bedroom in F & B Shaded White which is a very beautiful pale but warm grey - like a cross between a mushroom and a pearl! The paintwork is Slipper Satin which is a slightly grey, but warm off- white. I'm avoiding a carpet that's too similar in tone and opting for a weetabix/pale honey coloured natural fbre like jute or sisal, with an ivory-cream shagpile rug and shiny ivory cream silk curtains, to add a nice contrast of texture to the very rustic/organic flooring, and because it needs warming up with a tiny touch of yellow otherwise it could become too monochrome, a bit like a black and white photo, which is a bit disconcerting to live in!
If you want pale coffee colours and light oak furniture a good accent colour for cushions or lamps would be deep red, or most shades of blue, especially deep teal. Just a few tiny touches or you will lose the 'calm' of a good neutral scheme.