Our main practices are the five daily prayers (common to all Muslims) and different litanies for remembering Allah, like "La ilaha illAllah" (There is no god but Allah).
Yeah, writing down whatever comes to mind is good for this, and also looking back over past notes and comparing and contrasting them.By brainstorming I mean more like actively attempting to generate ideas rather than just letting them come to you. Some people make charts or lists for example. I do this a lot but I also will write pages and pages of freeform junk, basically just talking to myself, asking myself questions and giving a bunch of possibilities for answers and finding problems and addressing them. It's sort of like I'm bouncing ideas off myself since I don't have another person to do it with. Sometimes I'll even go for a long walk and record myself brainstorming out loud. But I write fiction so I don't know how useful it would be for "mathematical philosophy".
"It's sort of like I'm bouncing ideas off myself"
Exactly
I've also used audio recording (especially when I'm on a long drive and can't write).