Check moon position
Moon phase is only the first signal. Also check moonrise, moonset, and angular distance from your target. Even near new moon, a nearby moon can brighten the background.
Plan around astronomical twilight
For faint targets, treat the window between the end and start of astronomical twilight as your main imaging time. Brighter clusters or lunar work can use twilight for focusing and test frames.
Estimate target altitude
Low targets pass through more atmosphere. Planning exposures around transit usually improves guiding stability, contrast, and star shape.
Confirm the small parts
Batteries, dew heaters, cables, filters, and adapters are difficult to replace in the field. A short connection check the night before prevents many avoidable failures.