I mean I'm planning to travel around the world for one year, not RTW tickets. I'm trying to find the best possible way to plan one-way tickets to destinations from where I'd buy again cheap flights to other destinations. I understand that not always it would be the cheapest.

I know tools like kayak, matrix ITA etc. But I need some directions like: do I have to just search for the biggest airport hubs to get the cheapest flights to say "tropical" destinations? What are the cheapest dates through year for destinations.

Do you know some tools or at least blogs, charts for this problematic?