need a little lighting help!

O.K. so I got my sprout to grow and mature and am ready for the flowering stage, so my question is this when switching from vegetative stage to flowering stage do I need to just switch the lights to flowering lights or do I use both for a while to gradually make the switch? Also do I gradually change the light to dark ratio ( I'm using 18light/8dark for vegging and 12light/12dark for flowering) or just make a quick switch? And is there any better lighting ratios than mine or does it just depend on the strain of the plant?

I don't do it gradually. I just throw them into 12/12.

thanks for ur help

Yes on the day you want to switch to 12/12, let the timer go on as usual. Then switch the red switch (the one that turns off the lights) to the 12 hour interval you want while the lights are on. Good luck on flowering!