Yeah, there are many methods... e.g.:
[full name - short form]
Aleksandra - Ola
Olga - Ola
Alicja - Ala
Alina - Ala
Aldona - probably also Ala, but I haven't met any girl called Aldona... only in Machulski's comedy "Kilerów 2-óch" Aldona presented herself as... "Dona" (?).
Jerzy - Jurek
Stanisław - Staszek, Stach, Sta¶
Gustaw - Gucio (as in my case

)
Jan - Ja¶, Janek, Jasiek
Włodzimierz - Włodek
Władysław - Władek
Bogumił - Bogu¶
Ryszard - Rysio, Rysiek
Anna - Ania
Joanna - Asia
Magdalena - Magda, Madzia
etc., etc....
Some names are almost never shortened (unless we want to make them really tender, for example, when calling a baby, or our beloved...), such as Marek, Leszek (Leszek is also a short form of Lech, but that's a different name), Mariusz, Janusz, Paweł, Robert, Marta, (we don't have any Bob

) and many other names.