My own solution (links just quickly googled for example purposes):
Something like this (available at all good opticians): glasses cleaner
And some very soft lens/glasses cleaning cloths
No need to spend loads of money or worry about damaging lenses by destroying any coatings. The type of solution used for cleaning glasses really is just very dilute washing up detergent and if you have two glass cleaning cloths, you can use one for wet dirt removal and the other for drying and polishing.
Some other advice:
Importantly, never use dry facial (or other) tissue - their fibers are too coarse. It's mainly only at higher aperture values that specks of dust/dirt smudges really impact on image quality. You can experiment yourself by selecting aperture values above f10. Wide open, you will hardly notice.
Be ultra careful if ever you decide to clean the inside of the 'Through The Lens'/TTL camera viewfinder above the mirror. This is actually the focusing screen and is made of very soft plastic which scratches extremely easily. Just light fingernail pressure can permanently mark it. Not all focusing screens are user replaceable and cost upwards of £30 (plus any labour charges etc).
Try not to be too obsessive; all camera gear (in my view) is meant to be used and to an extent, abused. Any filters on the front of lenses can diminish image quality if not of pro standard. I think they can be good for certain environments but they can trap dust between the lens and the filter so can be a pain. Fitting a lens hood is a good way to protect lenses from scratching.