So... knowing Donald Trump's thought process and his current options fairly well, here's what I reckon is the best way to turn this situation to his advantage (I'm not saying this is ethically or morally right)

He needs to give a concession speech, from the Oval Office.

"I am instructing my legal teams to withdraw their litigation. In my view, the unreliability of the mail-in ballot system has delivered an unfair result, but for the good of the nation, I will peacefully leave the White House upon the inauguration of Joe Biden on January 20th...

"However, I am today announcing the beginning of my campaign to be re-elected as President in 2024.

"I look forward to holding Joe Biden to account for the next four years, before defeating him in the first rematch election since 1956."

Now, why would Donald Trump do this? Well, firstly, he has lost the 2020 election, and has so far not been able to unearth any evidence which will be accepted by a court that any widespread election fraud has occurred. This would allow him to leave without being forced to.

Secondly, far from the widespread repudiation of Trumpism the Democrats had hoped for, the election results have shown the President’s ideology was growing, not shrinking in popularity. While 63 million voted for him in 2016, he may end up with more than 72 million in 2020.

The Trump Brand is also strong, as Republican tickets with his name at the top outperformed 2018 midterm races where his backers in the Senate and House of Representatives were left to run on their own merits.

Some Republicans may wish to be rid of Trump, but if he decides to stay, he will be very difficult to defeat in a primary. An announcement of a 2024 run would make him the leading candidate in the race, by far.

Thirdly, being President in 2021 is going to be difficult for Joe Biden. The rollout of vaccine doses to 350 million people is unlikely to be entirely smooth. The economic recovery will be hard, and tremendously expensive.

Pending runoff elections in Georgia, the Democratic Party’s poorer-than-expected showing in Senate races across the country will mean the new President Joe Biden will likely be forced to negotiate all of this with Republican Majority Leader Mitch McConnell.

Joe Biden will struggle to heal the divisions this election has exposed. In two years time, he faces a possible loss of more seats in the Congress, making his job even harder. When the 2024 election cycle arrives, Biden will be in his 80s. He may decide not to run.

The Democrats, with their chronic inability to deliver predicted landslides and serious internal divisions, are no shoo-in to turn this victory into a long-lasting dynasty.

But what about Trump's legal and financial problems? There's widespread speculation that if he loses office, he may find himself entrenched in a years-long battle with prosecutors and creditors. But becoming the country's de facto opposition leader may shield him somewhat.

Prosecutors and creditors may shy away, fearing accusations that they are only motivated by political animosity. Democrats have spent four years decrying the "lock her/him up" chants which ring out at Trump rallies. Do they really want to lock up or bankrupt the GOP leader?

Will this happen? Maybe. Steve Bannon suggested weeks ago that it would: “I’ll make this prediction right now – if for any reason the election is stolen from or in some sort of way Joe Biden is declared the winner, Trump will announce he’s going to run for re-election in 2024”

Trump is reportedly already discussing a 2024 run with his advisors according to @jonathanvswan, who accurately predicted that Trump would declare victory on election night even if he was trailing. https://www.axios.com/trump-2024-presidential-run-4add0d86-02be-41f9-b2fd-5aaca96ce6ce.html?utm_campaign=organic&utm_medium=socialshare&utm_source=twitter

With Biden already starting the transition process and Trump's legal arguments floundering, this may be his best strategy.

“Trump’s best strategy” and “the thing Trump ends up doing” are often two very different things, though.