Hi,

Priorities:

1) Campaign

2) Campaign

3) Campaign

Do you have a 60 and farming brutal 12.3?  If no...

4) Campaign

5) Campaign

Post an image or list your champs, and someone can recommend who you should get to 60 first. 

Other considerations, mostly advice given to me.  Some I unwisely ignored...

a) Save all rares and epics. Don't use as food

b) Pay attention to Rhazin fusion, don't ignore like me (my biggest mistake). Make slow progress here as you focus on the above. 

c) Save gems. Mino isn't really worth doing until you can do mino15. Saving 800 gems will make you doing masteries easier.

d) Use Epic books wisely, they are very difficult to obtain

e) There are very good rares (Apothecary is #1 imo, be on the lookout for him)

Good luck.

I probably played this game differently for most people.

I did not focus in campaign. But i make sure I have a farmer. I focus on dragons. This is where I get my gear,. Never I tried gears from campaign. Since I enjoy arena unlike most people, I build arena champions first before focusing on other dungeons. I believe I only 3 stars everthing on brutal campaign when I can farm on 6 star artifacts. I only started to 3 star nightmare when I got Tormin. 

I never save rares except for voids since expanding vault is so expensive, I did not save rares that are not good since rares can be easily summon again. I only save 1 copy of each epics. Duplicates for me are free chickens. My peiority in spending gems are for dungeons not leveling champions. So I fed duplicate epics for food to save energy. 

And when I started farming level20 dungeons, I sell all 5 star artifacts and never save any 5 stars again. That is when I already have my team for all dungeons and arena team so no point of saving 5 star artifacts. To progress, I needed to upgrade my choice of artifacts to save. 

Faction wars is not my priority right now. I only farm on some factions that I can do.