I'm on my fourth generation guppies of my own line - Here's what I do. Maybe you can use some of this.
20 gallon tank - I did a 10 but I was way too successful and it was overstocked very quickly.
Gravel - I've had dark gravel, I've had light gravel - never seemed to matter
Plants - a few - never seemed to matter
Filter - *goes to check* Top Fin 20
Water temp - usually 78
Male to female ratio: currently 1 male to 10 females. I pick and choose my fish, and only the best looking male from the previous generation is allowed to stay and produce with the next generation. When I started, I had 3 males to 10 females.
Setup detail - I have a divider set up in the tank - leaving the right side (away from the filter - the water pouring down creates too much current for fry) available for fry and only fry. They don't need too much room. I took a regular old plastic guppy nursery from Petsmart and knocked out the bottom of it. It floats on the baby side - When a female is ready to pop, I move her from the left side to the right side. *MAKE SURE YOU PUT A LID ON THE NURSERY* This way, instead of having fry drop into the bottom of the nursery only to swim up and get eaten by their mother, they fall down into the tank and the divider keeps them safe.
Food - for the fry, BBS is best when they are very young. At about a month old I put them on powdered flake. Frozen krill about a month before they are ready to be moved to the left side (I move them when they are big enough to eat the newest fry being born)
Lastly...

Keep MonsterFish in another tank to eat any guppies you'd like to cull out due to any imperfections or unwanted coloring.
Good luck
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