Hi, so once you read ETWOLD (Exploring the World of Lucid Dreaming), you'll know what I mean by day practice.
"Practice" means just whatever you're doing to promote lucid dreaming skills. Day practice is in the day, night practice is in the night.

Day practices include: mindfulness, SAT, various forms of all day awareness / presence, reflection/intention moments, prospective memory exercises (both in ETWOLD), meditation, daytime MILD, visualization, intention setting, dream journaling, reading your dream journal, thinking about dreams, planning and visualizing your dream goals, etc.

Night practices include: noticing wakings, MILD, WILD, dream recall and journaling (at least keyword notes), setting intent, DEILD, things like that.

Mantras can be helpful if they're meaningful to you.

WILD tends to have a higher success rate at WBTB (generally 2nd half of the night), but if you can do it at bedtime, good for you!

MILD is good any time of the night or day. It's considered very powerful at WBTB around the 3rd cycle (depends on your dreaming/sleeping pattern).