Editor Beth Hill's article Mastering Scene Transitions. including advice such as...
Never change POV within a paragraph
Transitions can be short (two words. i.e. And then...)
They can be as long as a couple of paragraphs (But Ms. Hill cautions against anything longer.)
[N]arration is quite useful for transitions
Edan Lepucki writes 'Fluidity is what I long for, anyway, when I'm working; I want to feel like I'm "inside" of my own text, participating in its unfolding in a way that is intuitive, natural, and enjoyable. Being overly conscious of transitions gives me a distancing, jerky feeling that is the opposite of fluid.'
Ms. Lepucki goes on to examine how transitions are handled in books she's recently enjoyed.
Advise: '[S]pace breaks can provide a useful exhale before you transition to a new time frame or narrative register.'
Don't use transitions to substitute for scenes that are too difficult to write.
'If you're ever stuck in a scene, I suggest opening a favorite book, and seeing how the writer handles the problem.'
Ms. Lepucki ends her article with, 'Transitions might be the problem, or they might just be the symptom of a problem.'
Meaning: you may be having trouble transiting from scene to scene because you're not "in" your story or you haven't "investigated" your story enough or you're trying to avoid writing the difficult scene.
As the sun slowly set on Mayne Island, I picked up my pen and wrote the next scene.