Useful height, not empty height
An arboreal tarantula needs vertical structure it can actually use. Cork bark, tubes and anchor points matter more than creating a tall empty box. Arrange the retreat so the spider can move from the door into cover quickly.
Front access
Front or side opening enclosures are often easier because arboreals may web the top. A top-only lid can tear webbing every time you feed or refill water. Whatever door style you use, it must close positively and leave no sling-sized gaps.
Ventilation
Cross-ventilation is especially useful for moisture-dependent arboreals. Warm stagnant air combined with wet substrate can create mould and poor conditions. Use ventilation as part of the moisture strategy and adjust watering from substrate condition and drying rate.
Water and substrate
Provide a water dish even for arboreal species. Substrate still matters because it buffers moisture, catches waste and gives slings somewhere to retreat. Young arboreals may spend more time low in the enclosure than adults.
Webbing and retreat placement
Do not destroy webbing simply because it looks messy. The webbed retreat is the spider's secure zone. Give enough anchor points around cork bark so it can build a stable tunnel or curtain.
Rehousing
Plan arboreal rehousing carefully because speed and vertical movement can turn a small mistake into an escape. Work in a contained area, have the catch cup ready and guide the spider with the cup or a soft tool; never grab it.