I assume you mean our lovely UK-IMC/IR(R) rating. You want to stay proficient for procedures? Just do so.
When you are VMC and approach an airport with published approaches, just turn the radio on and ask whether it is ok to do so. If it is not a major airport with general restrictions, there is nothing special in AIP or NOTAM and traffic situation allows, I estimate the odds to be 90+% you get the permit from the tower. You can also save some money to ask for low approach instead of landing or T/G.
And no, it is not illegal to fly an instrument approach VFR. In contrast, most controller welcome this as part of flight safety. I quite often ask to use the approach procedure for VFR landing instead of traffic pattern and most of the times I get permission to do so.