So, I'm going through my m/s for typos and my Word for Windows spellchecker keeps questioning my use of a single word formed by putting two words together, such as snowcloud, cameraphone, bootscraper, etc. etc.

I don't in general trust Word's spellchecker for style as opposed to typos ('shrit' for shirt' sort of thing) so I'm consulting an ancient Oxford Concise dictionary as far as possible but not every word I'm looking up is in it.

I'm intending to self-publish so will be at some point hiring my own copy editor and not following anybody's house style (house-style?) but presumably it's then up to me to instruct the copy-editor if any of these things are a matter of taste.

In the dictionary, whether something has a hyphen, is all one word or is two words seems arbitary. For example, it's 'bootblack' but 'boot-faced'.

Anyway, I want to do the best job I can on my own work for now. Is there some mysterious heuristic about how to choose between the three options? Or do I have to look everything up in the dictionary? Does it even matter?

Is there some mysterious heuristic about how to choose between the three options?

I think it varies from pair to pair, with how long ago they started being put together, IYSWIM, and with lots in transition. If you read older novels - 30s, say - you find pairs still hyphenated which everyone now runs together.

I would go with your instinct.

If my instincts aren't operating I get out the Oxford Dictionary for Writers and Editors, and sometimes it tells me - often there's a UK/US difference - and sometimes it doesn't tell me, in which case it clearly doesn't matter a jot.

I would myself do:

snowcloud (by analogy with raincloud),

camera-phone (very new),

boot-scraper because it's evens with that and bootscraper but I like the separate parts showing... (But I've been known to write things like mis-apprehension...)

Thanks, Emma - instinct is good!

I got to 'snowcloud' via 'raincloud' as well. I originally had 'cameraphone' but the whole internet seems to have 'camera phone' but now I've changed it to 'camera-phone', which I prefer. I find it a bit disconcerting to think that someone is picking up a camera and then I read one more word and I've got to change my idea of what they're doing.

Bootscraper! Bootscraper! Because I can!

Thank you!