how can I synch files from iMac to MacBookPro?

I have an iMac and a MacbookPro - both only a year old using the latest Yosemite O/s update. I used DropBox and had been saving all files that would normally be found under Documents, to DropBox. However, it is a bit pricey for me and I was advised by so many people not to save that way (even though I have a time capsule).

I got scared a few weeks ago when I completely lost my writing folder - all my work in other words - so I transferred everything back onto the iMac. However, that defeats the purpose of my having a laptop to take with me when I want to write elsewhere, in a library, on the road and even in my outside studio if I want to, without having to save to USB and then copy across afterwards.

Is there a safe and reliable way anybody could recommend to synch. I don't think I can use iCloud Drive precisely because I use non-Apple applications (Word, Scrivener, Aeon Timeline and more).

Any suggestions, advice or help would be most welcome.

Thanks in anticipation