Book the desert safari for your first or second evening rather than your last. Dune bashing can leave some guests slightly stiff or sandy the next morning, better to have recovery time before a flight.
City tours like Abu Dhabi or Dubai's Old Town work well earlier in a trip too, since they involve less physical activity and are easier to enjoy while still adjusting to time zones.
If Musandam or Khor Fakkan are on your list, these full-day trips are worth scheduling mid-trip, they're long days and benefit from not being your very first or very last activity.
For a three-day trip, a common sequence is: Dubai City Tour on arrival day, Evening Desert Safari on day two, Abu Dhabi on day three before an evening flight.
However you sequence it, leave buffer time before any flight home, desert and mountain tours both run on estimated rather than fixed return times.