The biggest killer to headgaskets is detonation. Ways to prevent are to O-ring the block, this exerts a greater compressive load on the gasket when the head is clamped down. Use a gasket which is able to deform under load, something like a composite made up of steel, copper and asbestos. Something with a steel fire ring is recommended. Another option is to have slots milled in the block, although this is a fairly crude way of doing things any gas that gets past the gasket will not show any symptoms of headgasket failure. There are a few other more complex methods such as sleeving the block, or welding the cylinder head but for road applications virtually all of these is not worth being used. Take the fact that the headgasket is designed to fail, if it didn't you would have to replace the entire engine at more costly expense.