How to avoid sub optimal routing in ospf ?

First of all it will be very helpful for us if you share some scenario where you want to prevent sub optimal routing.

If we talk about single area, SPF is responsible for calculating shortest path among all routers, so there will be no sub optimal routing.If we talk about inter area scenarios Intra area routes are always preferred over Inter area routes.

For external networks ospf have forwarding address to prevent sub optimal routing.