I find that making last and going from there works the best for me, but you want to work on whatever point you have the most developed creative vision of. Make sure connectors to each area are thought about thoroughly, as bad connectors can ruin 5CP maps. Whereas Granary isn't a terrible map by any means (actually one of my favorites) it's connectors are hell to get through and promote defensive gameplay and stalemates.
A way to fix this is to add either 3 routes, as Process has. Or to add branching paths in your connectors, as Gullywash does (athough Gullywash is still stalematey in Highlander and Public games it is fine in 6s).