I don't train them as wingers - I train them as Trequartista to give them flair and finishing agility technique creativity then when im satisfied i might switch to poacher. Some crossing is good alot of crossing is great, but not necessary, but good to have. My players do have crossing, but not something I've trained.
These play inside forward for me -
Bale - E.Hazard -
James Rodriguez - J.Mata - Januzaj (Coming mega star) - Isco sometimes (bold 1st choice)
I will recommend for your first 5 players to develop their flair technique to atleast an acceptable level, just my preference. Take a look at C.Ronaldo in game and make a plan to see if you can develop your players simularly.
Same goes for my Strikers I want the Flair high and the offball movement and technique as well after that I want them to be quicker than Ronaldo

and when I'm happy strenght will be brilliant to have (complete forward).
Strikers from early development:
Trequartista
Poacher
Complete Forward
Inside forwards from early development:
Trequartista - Flair=20
Poacher - all the poacher skills high17-20
Back to Trequartista or complete forward
Hope it helps