Could I have some recommendations for good books on visualisation and/or some more general tips on it?

I'll be totally honest here and admit that I'm largely motivated by desire for personal entertainment - I would like to be able to 'direct' and view - with above-average clarity and, most importantly, as few interruptions as possible - 'movies' in my head, especially ones about toy- or cartoon-like epic battles or adventures So, lots of movement, sound and colour, and a good amount of detail - with the help of some external cues, whether visual, aural or textual.

I would try traveling out of body

Somewhere in the wiki is the accidental expert's guide

Otherwise, get your concentration really strong

I personally have had good luck with candle flame practice

Numerous threads on this site talk about kasina practices

Thanks, Daniel!