Oliver and Rust
See the magnetic towel rack here. You can also use command strips for a towel rack but keep in mind the weight limit that these command strips have. Most common weight for these are 3lbs while a magnetic rack can hold a lot more weight.
Another great idea are sliding shelves. These fit in most cupboards and make storing everyday items further back into your cupboard without having to worry about reaching behind everything.
There are many options for spice racks. We have found these to be very useful for small spaces.