Well, I was thinking of using [name_u]August[/name_u] because my mother’s birthday is in [name_u]August[/name_u]. If it didn’t sound silly with our last name, I would use [name_m]Archer[/name_m] to honor my father. His middle name is [name_m]Archibald[/name_m].
I wouldn’t use a variation of their names because then it would be too similar to my own name.
To honor my husband’s father, I would just use his real name [name_m]Vaughn[/name_m], because I have always loved it.
His parents divorced, so his mother wouldn’t like it though. I also love [name_f]Siobhan[/name_f], but not the spelling. Alternative spellings of [name_f]Siobhan[/name_f], emphasizing the von part, just look terrible. 
Honoring husband’s mother would be easy since it is a [name_f]Mary[/name_f] name.
[name_f]Yvette[/name_f]: [name_f]Eve[/name_f], [name_f]Eva[/name_f], [name_f]Evalina[/name_f], [name_f]Evangeline[/name_f], [name_f]Allouette[/name_f] (mn - my grandmother used to sing this to us)
[name_m]Fritz[/name_m]/[name_u]Freddie[/name_u]: [name_f]Winifred[/name_f], [name_m]Fritz[/name_m] (as a mn), [name_m]Judah[/name_m]
[name_m]Lothar[/name_m]/[name_m]Louie[/name_m]: [name_f]Eloise[/name_f], [name_f]Louisa[/name_f], [name_f]Louise[/name_f], [name_m]Luther[/name_m], [name_m]Lucien[/name_m]
[name_m]John[/name_m]/[name_m]Jack[/name_m]: [name_m]Jonathan[/name_m], [name_m]Ivan[/name_m], [name_f]Giovanna[/name_f], [name_m]Jack[/name_m] (if only it wasn’t so popular!), [name_u]Sailor[/name_u] (his occupation)
[name_f]Mary[/name_f]/Melwina: [name_f]Marigold[/name_f], [name_f]Maren[/name_f], [name_f]Maryse[/name_f], [name_f]Melisent[/name_f], [name_f]Mavis[/name_f], Marina, [name_f]Molly[/name_f], [name_f]Polly[/name_f]
[name_f]Susan[/name_f]: Shoshanna, [name_f]Susanna[/name_f], [name_f]Lily[/name_f], [name_f]Sadie[/name_f]
[name_f]My[/name_f] Grandmother’s MN is [name_f]Mae[/name_f] I plan to use the MN [name_f]Maeve[/name_f].
[name_f]My[/name_f] SO’s Grandmother’s MN is [name_u]Jean[/name_u], Right now we plan on MN [name_m]John[/name_m] for a boy (his MN is also [name_m]John[/name_m])
I love when people incorporate family names or honor someone in their family. [name_f]My[/name_f] sister-in-law’s family has a nice tradition, where the oldest daughter’s middle name is the mother’s first name. Our DS’s first name is my grandfather’s last name.