Besaid
I'm not quite so fond of the theme in Final Fantasy X for Besaid island - I prefer the theme in X-2! This piece didn't make the place feel warm or homely. Instead, I see Tidus running along the idealistic, bright, colourful paths with Wakka, Wakka pushing Tidus into the lake and the two swimming towards the village. The theme is bright, but fairly neutral, which reflects how Tidus feels about this new place. Around 1 minute 46 seconds into this, the long, quiet backing seems to convey how the features in a place can make us grow still as we sit perfectly still to admire them. Tidus is awed by certain features on the island and its beauty, but the place holds no connection to him, nor to the gamer.
Luca
Ah what a place! There's something very lively about it. The music conveys activity, excitement and sunshine.

There are still small sets of notes which bring to mind opening a chest or making a new discovery, but overall, the piece implies to me that Luca is a bright, sunny place bursting with activity.
Mihen Highroad
When listening to the track for Mihen Highroad, I visualise several people sauntering along a path lazily. Others skip along, pausing occasionally to admire the sights. The pace is quite strong and steady for the first minute, which brings to mind people marching along, aiming for a destination. When that rhythm falls away and transforms into something calmer (1 minute in), I see an expanding road ahead and scenery passing by - plenty of it, too! It rolls on and on...

But the strong rhythm returns. Someone/something has brought me back from my daydream and I continue to march.
The Blazing Desert
The majority of this piece is rather wavy, like the waves of heat one feels in a desert and the ripple-effect we can see. At first, the twangs feel like mirages, disturbing the perfect sea of sand. As the twangs continue, they melt into the sand, disappearing. The scene, endless sand, then feels more intense and the heat is unbearable. Around 1 minute in, there is a moment of relief. The area is calm. But it's still desolate!