All beautiful women have to work to maintain what nature gave them, and the older they are, the harder they have to work. But they start from the base level of being exceptionally pretty genetic females. From a TS point of view, the younger you are and the cuter you are (and some young males can be very girly-cute: think a young Johnny Depp) the easier it will be.
Then you get another kind of girl who may not be pretty to begin with but deliberately, almost ruthlessly uses every trick of make-up, hairstyling, diet and surgery to create the impression of sexiness. Think of the way that a plain, brunette New York girl called Stephani. Turned herself into the knowing parody of blonde sex-bomb Lady Gaga. It is much easier for a TS girl to become that kind of hottie ... tho it veers perilously close to the drag-queen look.
If you really want to know what's possible, the simplest way is to go online and check out the most expensive pre-op TS callgirls. Some of them are stunningly pretty (tho the photography has a lot to do with it). More of them have an artificial beauty ... But those proportions hold good for gg's too.
Good luck with your dream ... But be prepared to accept that for most trans-women it is just that: a dream. And, to repeat the point, remember that real beauty is just a dream for most XX-chromosome girls in the world, too.