I’m currently Stronghold, Mines & Farms @ 14, 3X TC@11, Forges @10,7,5, Barracks@2, Watchtower@12
My plan is to get SH, mines, and farms as high as I can, as fast as I can. More food production makes leveling up mines faster. More iron production makes leveling everything else up faster. (I had spare food to upgrade my watchtower, and since I’m on often enough to collect most its production instead of loosing it all to raids, I’ve got it fairly high. It produces more iron than a mine and more food than a farm for me, so that is worth it! If you log on less often, it won’t help you as much.)
Talking to an alliance member, food shortages may be in my past for a while, so perhaps I’ll let farms be a level down…or at least delay the upgrades until I’m chugging along on my next stronghold upgrade. I my second builder!!!
Next priority is training camps. Getting to 11 is HUGE; I did that ASAP, and quickly got my other two up to that level. Getting to 20 will be HUGE also, but that’s a long way away, and being halfway there early doesn’t do anything for me. I bought gems for a couple 10-pulls and got excess 3* heroes and sufficient 4* heroes. Without that in my budget, I might have actually researched and used TC10, and I probably would have made TC13 a priority despite the sucky odds (3~5%) of getting 4* heroes.
If I’ve got a bunch of feeder troops, an excess of food, and my best troops are all maxed, I’ll upgrade my barracks further. Building it was HUGE. Level 2 is doing me well enough right now.
Forges are fast, and mostly sitting idle so you don’t need to get more than one of them very high level. Upgrade them based on what you want to craft / can afford to craft. One is stuck at 5, to have a barracks on top of it. My titan loadout is Bear, Turtle, Axe, Arrows, and I occasionally use antidotes and mana potions. (I’ve got a LOT of healer heroes, so seldom use healing potions; YMMV) Having one forge at 7 (8 would be better, including the axes) lets me craft all those. I’m working one toward higher levels for really good stuff, but nothing below 19 (tornado) has me so excited I’ll keep it up to the level of my stronghold yet.
Last priority is storage, only done for NEEDED capacity to use/unlock a higher priority. (see above list)
I upgrade iron storage to what I need for my next stronghold level.
I’ve upgraded food storage so I can fairly easily hold the 273k food to ascend level 60 heroes, since I’m a long way to ascending a 5* a second time, both in items and in levels! (I’ll need 516k to get my watchtower over 12, and probably won’t bother 'till I can see a 773k 5* full ascension on my horizon…)
Recruit storage is a non-issue; I’m always stuffing them into a TC11 bank, 'tho I can hold 76 right now. I’ll need to get that up over 100 when I hit TC20… I might bump the highest one to level 10 just for the 5 gem mission reward before i need the space
The cool thing about letting stuff lag behind is that later on when your food and iron production is way higher, so what felt like a “big expense” when you didn’t do it for building or researching something 4 stronghold levels ago feels like pocket change when you get around to it.
There are other strategies besides mine, but I’m generally good at optimizing things like this.