Moon phase
Half lit, and named for a quarter of the cycle rather than a quarter of the disc.
These are associations the community holds, not settled fact — the more a reading is shared, the bolder it sits.
Confusion about this phase is entirely the name's fault. "First quarter" means the moon has completed a quarter of its cycle, not that a quarter of it is lit — half the visible disc is bright, which is why plenty of people call it a half moon and are not wrong about what they can see. Formally it is the instant the moon stands ninety degrees east of the sun.
Its timing makes it the easiest phase for anyone with a job. The first-quarter moon rises around noon and sets around midnight, so it is high and obvious through the whole evening, and needs no dark sky or early alarm. The line between light and shadow, the terminator, is where lunar craters throw their longest shadows, so this is also the best phase for a cheap pair of binoculars.
Practitioners treat it as the decision point. Something begun at the new moon has now met its first real resistance, and this is where it is either committed to or quietly dropped. Work suited to it is unglamorous: choosing, pushing, saying the thing out loud to someone who will remember.
Readings practitioners have offered, ordered by how many recognise them. Take what serves, leave the rest.
Carried forward
Common in contemporary practice
The phase most often used for a public commitment — telling somebody, paying the deposit, sending the message. The reasoning offered is that a half-lit moon is exactly as far in as it is out, and so is the practitioner.
Credit what you carry. Much of this comes from living traditions, and some of it from traditions that are closed — held by particular peoples and not offered for general use. Where you know whose practice a reading came from, name them; where you don't, say that too.