like a lot of new players who are learning DQ my first builds were random items, then crafted random items, crafted random items with Legend items, crafted random items with crafted Legend items, then all crafted Legend items.
I was always afraid of not having enough HP, but I recently made a 1 HP Wizard with 2x Glasscannon. it kind of sucks because it has some Reflect Damage in the build and also Mana Shield, which kind of defeats the purpose of having 1 HP in the first place. this is also a Farm Build, so it farms good, but it is slow. but I learned a lot for builds I Craft later.
there are so many combinations in DQ that it is kind of hard to choose just one. I think some players end up making that one good build and then are done, but I keep coming up with ideas with different combinations of affixes to try and want to see how they do.
@Mr_Scooty kind of says it best. look around the Forums for ideas, write it down on paper to see what you can fit on your Gears, and go from there. about half of my builds I made then tweaked, and the other half I wrote them out first before building them, and tweaked them later where it was needed.
you can boost damage directly, like using +100% Weapon Damage (increasing the damage of an attack), or indirectly for DPS, like using +15% Attack Speed (attacking two times a second instead of once). here is a post that should help you when you use Crystals.