If you need only need to keep a few Memories of Light of hand for Mirror-March purposes, a Reprehensible Lizard is a good option. Periodically you get a card where you can feed it beeswax, which on a success decreases nightmares and nets 4 Memories of Light. Until I got to a point where I could reliably get enough 50 pence items for side-conversion that was my standby.
That being said–side conversion is nice because you get 51 for 50, so you can keep a single Memory of Light and move the other 50 on to something else.
edited by Breckner on 10/14/2014