The embarrassingly high number of times I've played KotOR means that these days I'll tend to just go wherever capricious whim takes me rather than attempt to apply any reasoned thought or strategy to it. (That said, I tend to pick a couple of companions as the "main" ones in a playthrough and if Bastila's one of them, I'll leave Korriban 'til after she's been kidnapped by the nasty Malak Spleen since she refuses to set foot on the reeking planet of evilists and thus you have to use another companion anyway).
But, years ago, when I applied any real thought to it, it often went something like this...
TARIS:- I started here because seething evilists shot down the Endar Spire before I was able to hijack the vessel and take it elsewhere. Every damn time I got to the bridge, the debased navicomp blew itself up with eerily unhelpful timing before I could use it.
DANTOOINE:- I went here next because Bastila said to. And she's cute, so who am I to argue? Also, there's that small matter of it being the only listed planet in the entire universe at this point (except one that's just been completely rubbished by the Sith Fleet).
MANAAN:- I chose this first a number of times for many high, incomprehensible, deep, strategic, tactical reasons... well... actually, mostly because it's a really nice blue colour on the navicomp display... Having been lured here by its pretty blue colour, I would invariably then become irate due to the smug and annoying Republic governor bloke, Roland Wann or whatever his name was, who was somehow able to single-handedly drive me to the point of wanting to destroy the entire Republic with his irritating refusal to help me save it until I'd run round like a thrip covering up for the whopping mess he'd made of everything... So I always took great delight in blowing up his kolto facility almost as much to annoy him back as for the clear and pressing environmental concerns of helping the Giant Orange Firaxan of Doom... So, it was good to get that out of the way first and know that one was safe from being arrested by demented, parochial Fish for the rest of the game.
KASHYYYYYYYYK (or however many Ys it had):- Often stopped here next because I like forests and Juhani likes it too. Also it gave me the opportunity to callously abandon Zaalbar to his farcically named hairbag brother, Chundar. (Chunder being slang for vomiting, you've got to wonder about that name...). Abandoning him means not having to listen to him whinging on about theft of food supplies aboard the Ebon Hawk instead of actually investigating the matter himself if he's so darn concerned. Also the mad old coot, Jolee, can be obtained here and then he can entertain the crew with his endless wealth of rubbish anecdotes.
KORRIBAN:- If Bastila wasn't one of my chosen companions, I came to Evilist World next on the vague assumption that the longer you left it, the more likely that some reeking Sith Spleen would recognize you from their intelligence reports and thus cause serious trouble... But fortunately, the Sith's information network was completely pants and the incompetent evilists NEVER twigged who you are... which is odd really. You'd think that some report of the Ebon Hawk's activities would have reached what's apparently one of their most important planets, wouldn't you? Thus you'd imagine when the ship landed there in plain view on their doorstep and next thing someone's wandering round with a touchy-snarly Cathar and a mouthy Twi'lek street urchin that sooner or later, eventually, the mighty Sith security forces would sit up and take notice. But no. They're all on lunch break and Evilist Union Rules say they can't go and deal with their boss's arch enemies while they're on their near perpetual lunch break.
Also, there are some useful artefacts to be thieved from the Sith tombs.
YAVIN IV:- Old Whassname's space station would commonly be visited around now because I'd invariably forget it existed until this point.
MALAK'S SHIP:- Not really much choice involved here, as the seething evilists, desperate to make up for their deplorable incompetence in not spotting me on Korriban would hijack the Ebon Hawk and subject everyone to hideous torture in their underwear. Perverts... Everyone, that is, except Juhani, who would gleefully prove that the evilists ARE still incompetent by mushing all the guards and rescuing everyone.
DANTOOINE:- I would often end up here last in order to delay as long as possible the total infestation of my ship with hordes of Gizka, just STACKED. I know you can cruelly poison them all, or stamp on them and crush them to a paste, but it seems a tad nasty. I mean, it's not THEIR fault they're a cabal of creaking, bulge-eyed, faintly batrachian globules, is it? And they didn't put themselves aboard the Ebon Hawk... Anyway, once all the dashing about in the sand has been accomplished, I'll generally pop back to Manaan to sell all the wretched Gizka to the zoologically-uninformed Fish who wants to start a zoo. (Dantooine would be earlier with Bastila, though, in order to find her wrongly maligned mother).
RAKATA PRIME:- Obviously, the moment you discover where it is, heading here seems quite urgent due to that whole Evilist Conquest of the Entire Galaxy thing... though given their filthy incompetence thus far, one probably shouldn't be worried.
STAR FORGE:- Naturally, since it's heaving with depraved homicidal maniacs and unfeasibly vast numbers of machines programmed to kill you whilst your own star fleet tries to blow it up, you come here. A very sane choice, I'm sure.