At least when I was breeding pet/show, the roman nose was discouraged. But perhaps like the ears, maybe that's changed. The NFRS is based in the UK. In the US I know AFRMA is still active, and as far as I'm aware they still judge against the tulip ears. There might be a couple other active clubs in the states, but I don't really know any more. That's one thing about the standards, each club kind of makes up their own.

While you go about your project, take notes on EVERYTHING. And photos if possible. That way you have something you can go back and refer to as you learn. If you keep notes, records, and photos of your litters, including which babies you keep, you can also keep track of progress you make. Most physical traits are polygenic, as opposed to the simple single genes that control most colors (yes, you can combined color genes to make more combinations, but most colors are created by single simple genes). This makes physical traits a little hard to select for, and it takes a little longer to get the trait cemented in, but it is possible. The key is picking the best of the best. Don't even try to "even" things out, for example picking a very short nose and a very long nose and breeding them together to get "just right". It usually doesn't work that nicely. Instead, select two of the best noses (or whatever trait) you can, and breed those. Then from that litter, select the best and breed back to the best (even if it means breeding to a relative). Keep track of what's produced, and learn from your mistakes. You will make mistakes, we all do. Learn from it, improve the next time, and move on.

I'll have to see if I have any baby pictures uploaded that I can share to give some examples of what to look for.