I think you would be better off planning your tile layout floor to ceiling while considering the best tile layout to include the niche. The niche doesn't necessarily have to be exactly on grout lines but may look better if it is planned that way. If you use bull nose tiles on the outer corners of your niche, the grout lines will be just inside the niche which gives a a more finished look.
There are lots of videos on building showers and niches on YouTube, you just need to find one that best fits your situation and read the comments because some of the videos are made by people who don't know what they are doing and people will call the out on it in the comments. If they have disabled the comments, that's a big red flag.
There are lots of videos on building showers and niches on YouTube, you just need to find one that best fits your situation and read the comments because some of the videos are made by people who don't know what they are doing and people will call the out on it in the comments. If they have disabled the comments, that's a big red flag.