This is my first IKEA hack. I bought a Grundtal 800 mm shelf to put on the wall but then thought I'd try and utilize space over my kitchen bench by putting two uprights and mounting shelves back to back. The next step was adding Grundtal countertop lighting which worked really well I think ( it's a perfect fit ).
Uprights are 25mm / 1" chrome plated tubes that I bought from a local hardware store with a pair of flanges each. While strong enough by themselves I decided to add wooden dowel as inserts, they only had 19 mm Tasmanian oak dowel - a bit of gaffer tape for a snug fit did the job. Drilling holes was the trickiest part, this is when a pedestal drill ( that I did not have ) would come in handy. I made a template from a piece of timber ( an inch hole to thread the tube in and a 1/4 inch hole at the right angle to use with my hand drill ).
I used 1/4" 38 mm bolts with spring washers and dome nuts for the main assembly, 1/4" proved to be too big for the Grundtal lighting so I got a 3/16" ones for that ( I had to shorten those by about 5 mm to use dome nuts ).
Installing a Grundtal countertop lighting panel ( 3x halogen globes ) was a piece of cake. I got two plates that I bent into a 'C' to curve around the rods of the shelves then screwed them to the panel. It fits snugly but can be lifted up if needs be. As a bonus it fills in the gap between the shelves ( not full 800 mm, however ). I could have threaded the cord ( 'Ansluta' ) through the upright to hide it but there is a dowel inside so I did not bother.
I do not keep anything extra heavy on these shelves*, as you can see it is mainly plastic Tupperware ( stuff that we use often ). But it is sturdy enough to handle pots and pans if I wanted and I added a few Grundtal extras to hang off the bottom shelf. Shelves were the most expensive part at 39AUD each, lighting 69AUD plush 10AUD for the cord, tubes and dowel about 20AUD per upright, add bolts, nuts and washers at about 3AUD per pack.
P.S. As mounting shelves back to back is obviously optional a similar design could be used when you would not want to screw shelves straight to the wall - for whatever reason, e.g. you do not want to drill through the tiles or maybe even want those against a window etc.
P.P.S. * - I now keep a massive 3kg Scanpan pan with a glass lid on the shelf