[Fantomen]

On one hand it's good to search early to get more gems out of each site, on the other hand this makes you a juicier target (in MP).

The best manual searchers are those with many high paths of course and if possible good mapmove or flying. LA Caelums Harab elders are amazing site searchers for example. This often (not always) means your capital mages are quite good site searchers, use the cheap low path mages from other forts for researching.

It is a good idea to be a bit anal about which provinces to search first, especially with remotes. For example cast dark knowledge on unsearched swamps and wastes before targeting other provinces, haruspex at forests and so on. Same goes with manual search.

Match you site searching strategy with your research goals and overall strategy. Don't waste research turns on gems you don't have a plan for early on.

Keep track of the magic sites setting, the lower the sites setting the more streamlined your search strategy needs to be, and the less return in trying to dig out a third or fourth site in a province.

If your mages are bad searchers, then let other nations do the searching for you. Focus on building a strong army instead, and research offensive spells that don't cost gems. Then look and the gem income graphs and attack one of the leaders.