Slash costs/headcount in short term, sell, pocket the cash and get the hell out of dodge.

There are plenty of due-diligence internal things that need to be put in order to make your company attractive. Processes, documentation, compliance, etc.

Then there are things like having roadmaps for the future to make you look attractive.

Then there are vulture things to make your numbers look good which can range from doing neglected cleanups of actually unnecessary costs to cutting costs in ways that really suck for customers and employees.

Produce attractive numbers. Often by cutting costs.

Aside from things mentioned by others: Having a network to potential buyers.