When it comes to mounting fixtures, some of you are lucky enough to be able to mount directly to the wall while others like me are less fortunate and have to get creative with how we mount our lights. I have been using wooden boards screwed to the ends of storage racks to mount my lights but I'm running out of options so I was wondering what things you have done in this situation.
I need some ideas so I can get some fixtures mounted and run power to them.

Some people have built mini light poles with weighted bases to mount their lights with without drilling into walls. You should be able to find most of the materials needed from a hardware store/DIY shop.

It'll work pretty well for lighter fixtures, particularly remote ballasted ones with the ballast mounted in the base to weight it down but you probably should use addition weights regardless.

It'll make for a pretty sick looking floor lamp IMO.

I've thought about that and I have very limited floor space.
Apart from the wooden boards, I have made a few mounts that slide into slots on my storage racks but even those have their limits. I know some people mount fixtures one above the other but I don't have enough height to do that. I can physically mount more to the uprights but I don't want to because it will create a head bump hazard. I do have a couple of places where I could mount lights but I still need to make suitable mounts.
I do have a mounting pole for a TV antenna that I plan to use as an arm. I may also rearrange what I already have mounted so I can mount some short arms under the long ones.
I was also thinking about screwing some long lengths of wood to my bed frame and mounting lights that way. These would only be for fixtures that aren't too heavy.