Use it to get till 90 and go for 90dun. Then save it.

From level 100 onwards you can also do siauliai missions, while continuing 90dun.

Then followed by 115dun, 130dun and 145dun. You might have difficulties in getting parties for these dungeon, but just try. If no one, and if you have time then continue doing quests near your level or from those maps which you have skipped. DO NOT POP exp cards here. Also remember to do missions.

Till around 165, then there is a huge void from 165-190. As dungeon 160 exp is not worth and 175 exp is so-so. From this level range go back to questing from maps around your level so that you will have higher exp cards. Pop exp cards if the map is too difficult. Also remember to do missions. If you ran out of exp cards, daily missions are your savior. Just have to bear with this, level 165-190 is the worst leveling experience currently, until the KTOS dungeon level entry patch comes.

Then 190dun till 210. From level210 onwards grind is faster than dungeon. Also remember to do missions

PS: I think you can see how many times I repeat doing missions.