Eternal (Green) - Normal, Epic, and Legend affix values are doubled. Item Quality is automatically +50%.
Crystalline (Cyan, Light Blue) - Crystal Items are Legend or Eternal Items that are found with a Crystal affix. Obsidian Crystal can be used to place a Crystal affix on any Item except Eternal and Pets. only one Crystal affix can be on any Item. Crystal affixes are triple the value of their Epic affix versions, except for HP/MP on Hit, which are only doubled.
Mythic (Purple) - these Items have 4 Sockets on them, or you place Sockets on them using Zircon Crystal. go to Codex > Mythics > choose a mythic affix. these are the recipe lists. each Mythic affix requires 4 Mythstones to create. if you only see ? ? ?, this means you haven’t unlocked the recipe yet.
the very first thing you should do is read the Codex > Affixes and change Epic affixes to other Epic affixes. this is the cheapest & easiest way to learn about affixes. even better, just make an all Epic affix build and play with it, changing Epic affixes when you want to see different combinations or just to see how they work.
after you you have a better understanding of how affixes work, look for Legend Items that best fit the build you want to start with, changing any affixes to better affixes that fit your build.
on lower floors & difficulty levels Health, Armor, All Resist, Regeneration and on Hit are all you need for survival. on higher floors & difficulty levels Dodge, Block, Sanctuary Mythic, Crowd Control (like Stun or Knockback), conditions that cause the enemy to Miss, maneuverability are more important. some players have high floor builds with only 1 HP.
change Fire DMG % to Epic +100% Weapon DMG %. this will improve DMG a lot.
change Fire DMG + to Epic +40% MP Reduce. costs less Mana to cast Meteor & Comet.
change Weapon DMG + to Epic +40% MP Reduce. lowers Mana cost of Shatter.
change Ice DMG % to Epic Dodge +10%. higher chance for enemies to miss you.
change Socket to Epic +15% Critical Chance. better chance to do +50% Critical DMG
change Fire DMG % to Epic +15% Dodge. even more defense.
change the Socket to Epic +15% Crit Chance. better chance to do Critical DMG.
Head & Amulet Items. for these, find ones that have Legend +100% Elemental DMG (one that you will change to Fire and the other to change to Ice) to greatly improve the DMG of Meteor & Shatter.
on both of these Items, you will want to have:
Epic +75% Critical DMG. two of these plus the base +50% Crit DMG will give you +200% Crit DMG when you make a Critical Hit.
Epic +30% Weaken. two of these will give you a +60% chance to do +60% Weaken DMG.
if you have a Pet, put one more Weaken for +90% Weaken, +10% Dodge, +250 MP on Hit.
when I was new to DQ, I spent months just having fun and making lots of different combinations, and I only had 1 Character Slot, so when I had an idea for a different Class, I deleted the one I had and started over. I did this a lot! then I discovered DQ Forums and did a lot of reading, which made me read the Codex a lot also.
this is only a little help, but hopefully it will help you put your own ideas into the Characters and watch them grow!