Using the wrong enclosure style
Mexican Rose Greys are terrestrial. Young spiders may dig more, while larger animals often spend more time in the open, although individual Tliltocatl verdezi can still choose to remain hidden. Build the enclosure around that lifestyle instead of using the same shape for every tarantula.
For Tliltocatl verdezi, adult size is about 14–16 cm (5.5–6.25 in), but enclosure size should still follow the spider's current size. A sling does not benefit from being placed straight into a large adult setup.
Getting moisture wrong
For Mexican Rose Greys, keep the enclosure mostly dry, with to lightly moisture-retentive with a water dish. The mistake is usually treating the whole enclosure as either permanently wet or permanently dry instead of watching how the substrate actually behaves.
Keep fresh water available to Tliltocatl verdezi. Persistent condensation, a stale smell or wet substrate that never dries are reasons to reduce water or improve airflow.
Overfeeding or chasing a schedule
Feed Mexican Rose Greys according to size, appetite and abdomen, not because a calendar says food is due. Tliltocatl verdezi can refuse meals for normal reasons, especially around premoult.
Do not keep adding prey when a Mexican Rose Grey is already very well fed. Remove ignored live feeders and offer food again later.
Disturbing premoult or moulting
When Tliltocatl verdezi shows premoult signs, remove live prey and leave the spider alone. A closed retreat is not an invitation to open it and check what is happening.
After a moult, wait until a Mexican Rose Grey has hardened and the fangs have darkened before feeding. Larger spiders usually need longer than tiny slings.
Making maintenance too difficult
A good Tliltocatl verdezi enclosure lets you refill water and remove food remains without dismantling the main retreat. If every job requires moving cork, digging into substrate or working directly over the spider, change the layout.
Handling is not part of routine care for Mexican Rose Greys. Use long tools when useful and have a catch cup ready for rehousing.
Changing too much at once
Once a Mexican Rose Grey has settled, avoid repeatedly rearranging the enclosure for appearance. Stable housing usually matters more to Tliltocatl verdezi than a constantly changing display.
If something needs correcting, change one clear husbandry problem at a time. That makes it easier to see whether Tliltocatl verdezi settles, feeds and uses the enclosure normally afterward.