Hi mate ....
Is it your first job - then if so not bad.
A few pointers, questions.
Were the tiles diff sizes - you seem to have had problems, some do not seem to line up properly.
Ceiling height - some of your cuts are stepped - seem to have a rather large bead of Silicon going round the top - One tip is either going from left to right or right to left, measure one side of the next tile from the one you have just cut, that way any changes in size are not as noticeable.
What's going on with the border ?
Sorry, I do not intend to be harsh. Good luck for the future