On wooden/painted floors, I have also used plain matte finish Scotch tape to give the spikes more longevity, without the glare that clear packing tape leaves. It doesn't stay quite as well, but it's always on my preshow checklist to check the spikes anyways.
I've also had some success with glow paint. I did A Delicate Balance this past year, and the designers were very set against seeing big strips of glow tape in the refined living room set. Some structural set elements, I was allowed to paint right onto, while other nicer pieces of furniture I put down a piece of the matte Scotch tape, then a fine line of glow paint on top. The best was this faux marble table that one of my actresses had to cross past the downstage edge in blackout to get offstage--my compromise with the designer was that I painted a bit of my glow paint into the veining, so that it gave just enough of a glow for the actress to see it.
