I love names a little unheard of but with common simple nicknames. So far I have found [name]Bennett[/name] nn [name]Ben[/name] and [name]Emmeline[/name] nn [name]Emme[/name]. Please add more names with the similar trend, thanks 
My faves:
[name]Emerald[/name], NN [name]Emmy[/name]
[name]Susannah[/name], NN [name]Susie[/name] or [name]Suki[/name]
[name]Imogen[/name] or [name]Genevieve[/name], each NN [name]Gen[/name] ([name]Imogen[/name] is uncommon in the US, it’s quite popular here in [name]Oz[/name])
[name]Cassia[/name] NN [name]Cassie[/name]
[name]Minerva[/name], NN [name]Minnie[/name], [name]Mina[/name].
I also like a lot of the -bella names, and rose- names especially Rosabel (hey it’s both, I had to like it) and [name]Annabel[/name], [name]Mirabelle[/name], [name]Rosemary[/name] and [name]Rosamund[/name]. They’re not the most popular names in each category.
[name]Benedict[/name] ([name]Ben[/name])
[name]Samson[/name] ([name]Sam[/name])
[name]Edison[/name] ([name]Eddie[/name])
I love [name]Imogen[/name] nn [name]Genny[/name] or [name]Ginny[/name] and [name]Genevieve[/name] nn [name]Genny[/name]. I also like [name]Annie[/name] for [name]Susannah[/name].
[name]Anastasia[/name] nn [name]Ana[/name], [name]Evangeline[/name] nn [name]Eve[/name], [name]Eva[/name], or [name]Evie[/name].
Some of my favorites are:
[name]Cadence[/name] ([name]Cady[/name] prn. [name]Katie[/name])
[name]Florence[/name] ([name]Ren[/name])
Hosanna ([name]Annie[/name])
[name]Charlton[/name] ([name]Charlie[/name])
[name]Marcellus[/name] ([name]Marc[/name])
Seems like there are more I like…maybe they’ll come to me.
[name]Geneva[/name]- [name]Eva[/name], [name]Jenny[/name]
[name]Rosalind[/name]- [name]Ros[/name], [name]Lindy[/name]
[name]Mariella[/name]- [name]Mari[/name] and [name]Ella[/name]
[name]Philomena[/name]- [name]Mina[/name]
[name]Marcheline[/name]- [name]Lina[/name]
[name]Cerise[/name]- [name]Reese[/name], Reesy
[name]Pandora[/name]- [name]Dora[/name], [name]Andy[/name]
[name]Emerson[/name] nn [name]Emme[/name]
[name]Imogen[/name] nn [name]Ginny[/name]
[name]Susannah[/name] nn [name]Sunny[/name]
[name]Magdalen[/name] nn [name]Maggie[/name]
[name]Mercedes[/name] nn [name]Sadie[/name]
[name]Miranda[/name] nn [name]Annie[/name] or [name]Mira[/name] or [name]Andi[/name]
[name]Antonia[/name] nn [name]Annie[/name]
[name]Halcyon[/name] nn [name]Hallie[/name]
[name]Indigo[/name] nn [name]Indi[/name]
[name]Bellamy[/name] nn [name]Bella[/name]
[name]Cobalt[/name] nn [name]Coby[/name]
[name]October[/name] nn [name]Tobi[/name] (for a girl) or [name]Toby[/name]/[name]Tobey[/name] (for a boy)
Wilkins nn [name]Will[/name]
[name]Benedict[/name] nn [name]Ben[/name]
[name]Alaric[/name] nn [name]Ricky[/name]
[name]Angus[/name] nn [name]Gus[/name]
[name]Crispin[/name] nn [name]Cris[/name] or [name]Kip[/name]
[name]Carleton[/name] nn [name]Carl[/name]
[name]Davis[/name] nn [name]Dave[/name]
[name]Elliot[/name] nn [name]Leo[/name]
Emeric nn [name]Ricky[/name]
Zeben nn [name]Ben[/name]
Zajac nn [name]Jack[/name]
Olivander nn Oli
[name]Granville[/name] nn [name]Grant[/name]
[name]Hayden[/name] nn [name]Hayes[/name]
[name]Lennox[/name] nn [name]Knox[/name]/Nox
[name]Huxley[/name] nn [name]Huck[/name]
[name]Jeremy[/name] nn [name]Remy[/name]
[name]Malachi[/name] nn [name]Kai[/name]
[name]Reuben[/name] nn [name]Ben[/name]
[name]Thaddeus[/name] nn [name]Teddy[/name]
[name_f]Acacia[/name_f] nn. [name_u]Casey[/name_u]
[name_f]Florence[/name_f] nn [name_u]Rory[/name_u]
[name_f]Marigold[/name_f] nn [name_f]Mary[/name_f]
or you could go the other way, common given name with uncommon nn.
Like:
[name_f]Catherine[/name_f] nn [name_u]Wren[/name_u]
[name_f]Eloise[/name_f] - “[name_f]Elle[/name_f]/[name_f]Ellie[/name_f]”
[name_f]Jillian[/name_f] - “[name_f]Jill[/name_f]”
[name_f]Wilhelmina[/name_f] - "[name_f]Minnie[/name_f]/[name_f]Winnie[/name_f]’
[name_f]Guinevere[/name_f] - “[name_f]Gwen[/name_f]/[name_f]Evie[/name_f]/[name_f]Eva[/name_f]”
[name_f]Rosalind[/name_f] - “[name_f]Rosie[/name_f]”
[name_m]Benedict[/name_m] - “[name_m]Ben[/name_m]”
[name_m]Sebastian[/name_m] - “[name_m]Ian[/name_m]”
[name_m]Kendrick[/name_m] “[name_m]Ken[/name_m]/[name_m]Kenny[/name_m]”
Calderon nn [name_u]Cal[/name_u]
[name_m]Ebenezer[/name_m] nn [name_m]Ben[/name_m]
[name_m]Phineas[/name_m] nn Phin
[name_m]Angus[/name_m] nn [name_u]Gus[/name_u]
[name_m]Nicodemus[/name_m] nn [name_u]Nico[/name_u]
[name_f]Bethel[/name_f] nn [name_f]Beth[/name_f]
[name_f]Andorra[/name_f] nn [name_f]Annie[/name_f]
[name_f]Magnolia[/name_f] nn [name_f]Maggie[/name_f]/[name_f]Meg[/name_f]
[name_f]Andromeda[/name_f] nn [name_u]Andy[/name_u]
[name_f]Marietta[/name_f] nn [name_f]Mary[/name_f]
[name_f]Callie[/name_f] from [name_f]Calliope[/name_f] or [name_f]Calista[/name_f]
[name_u]Jess[/name_u] from [name_f]Jessamine[/name_f]
[name_f]Betty[/name_f] from [name_f]Bettina[/name_f]
[name_f]Mary[/name_f] from [name_f]Marigold[/name_f], [name_f]Marisol[/name_f], [name_f]Marianne[/name_f] etc
[name_f]Nicci[/name_f] from [name_f]Nicolette[/name_f]
[name_u]Dani[/name_u] from [name_f]Danica[/name_f]
[name_u]Jo[/name_u] from [name_f]Josephina[/name_f]
[name_u]Mel[/name_u] from [name_f]Amelia[/name_f], [name_f]Emilia[/name_f], [name_f]Melody[/name_f] etc
[name_f]Carrie[/name_f] from [name_u]Carmen[/name_u], [name_u]Carmine[/name_u]
[name_f]Ellie[/name_f] from [name_f]Elspeth[/name_f]
[name_f]Tess[/name_f] from [name_f]Thessaly[/name_f] is a favorite of mine.
Callidora- [name_f]Callie[/name_f]/[name_f]Dora[/name_f]
“[name_f]Sera[/name_f]” from [name_f]Seraphina[/name_f]
“[name_f]Mary[/name_f]” from [name_f]Marietta[/name_f]
“Pi” from [name_u]Piano[/name_u]!*
*joke from another thread
I second “[name_f]Sera[/name_f]” for [name_f]Seraphina[/name_f]
I love “[name_f]Cadie[/name_f]”(prn. [name_f]Katie[/name_f]) for [name_f]Arcadia[/name_f]
Casella - [name_f]Cassie[/name_f]
[name_f]Carina[/name_f], [name_f]Charis[/name_f] / [name_f]Karis[/name_f], [name_f]Kerensa[/name_f] --> “[name_f]Carrie[/name_f]”