The ones I have a hard time using are the kits I buy during retirement sales. I only buy ones I know I can use, but find I rarely use something after they are no longer relevant or can no longer be used for challenges (that's why I try to also only pick up retiring collabs with someone who is still in the shoppe).
The kits I haven't used are ones I bought with no idea what I will use them on (ie: the stunning christmas bundles that are released every year), and a lot of the FWP kits, because again they weren't obtained for a purpose..... I am trying hard this year to use all the kits in my stash at least once, the more I use, the less guilty I feel about my collection and the more I feel justified when I make any new purchases.
