I once had an entire bicycle frame and rims (irregular banding) covered in 3M Scotchlite reflective sheeting - the reflective material which is printed and applied to LEO vehicles and road signs. Although it was basically "maximum reflectiveness", this still was not as efficacious as a few decent taillights for night use. Reflectors (and most taillights) do very little for daytime bicycling safety. For day safety you need proper fluorescent-dyed lime or orange ANSI safety apparel. I used long sleeve Alertshirts for years, like these. The long sleeves increased visibility and provided some UV/sun protection. You can now buy similar apparel at Walmart or Target.

I find hi-viz apparel alone is not enough for daytime safety. I think it's prudent to supplement with a flashing headlight, like a Magicshine, plus a super-bright flashing taillight, of which all I tried seem inadequate until i got the DesignShine 500. You can certainly get by with multiple inexpensive taillights at night away from high-traffic urban areas, but for day use and some night use you really need a lot of flashing red light - either a Dinotte Daytime Red (DDR) or a DS500.

The DS500 costs more but has nearly infinite adjustment of light intensity and duration (flashing). The DDR is perhaps half as bright as the DS500, and for night use you can't run it in flash mode safely because the light intensity can't be turned down on flash. You can operate the DDR in continuous mode at 25, 50 or 100% output, but only in 100% output in one of three flash patterns. So basically you can't flash the DDR at night because it's too darn bright. I suppose you could point it downwards instead of straight back. Between these two taillights, I think most would rather pay another 10-20$ for the DS500 and have the option of about twice the output of the DDR for improved day use with the control capability to turn it down both intensity and duration-wise to suit night time needs.

If you haven't noticed, the latest trend in marketing cars and trucks is to include a small (or not-so-small) central console touch-sensitive computer screen to integrate lots of control functions such as hvac/nav sys/audio sys/cell phone. They're also starting to put HUDs in vehicles, so the motorist has their speed/outdoor temp/nav directions displayed almost directly in their line-of-sight on the windshield. This means before long all motorists will be as highly distracted as LEOs are now with their laptops 2 feet away glaring in their eyes, destroying their night vision and clearly distracted from the primary task of driving safely. I think bicyclists will need brighter, flashier taillights (i.e. Really Serious Taillights) in the future to have any chance of capturing some of the attention of the motorist in their ever-more-distracted state. Reflective tape and $25/50 lumen taillights are not going to do the job on roads with speed limits above 25 mph.