The number of mines and tier 1 ressources is very limited. OK you can upgrade to the advanced versions and double the production. I don't tell about level up the mines - one should do this to level 7 until player level 20 and level 10 for iron and stone on level 30. Not to forget to get about 6000 ressources per day by assisting friends (assuming you have more than 150 wich shouldn't be a problem). But assisting many friends is time consuming...
So what i'm talking about is concrete, lumber and steel:
- Lumber: You can occupy on Artificial Ponds. But these are popular. Ideal is the additional gold you get as reward.
- Concrete: There's no good way to obtain concrete other than assisting or occupying on Concrete Plants/Adv. Concrete Plants. As i mentioned above assisting is time consuming and limited. When you need concrete - especially to donate in boss strikes - others will need it, too - and most players won't allow to occupy this plants.
- Steel: Steel is easy to get by assisting Steel Mills (limited and time consuming) or occupying them or occupying other buildings or decorations - best results for the Missile Silos (also popular and rare). As steel is needed to heal and repair units during events the occupation capacity is limited.
So the solution to enhance the ressouce production is having players/accounts not intended to fight and do the missions but offer occupation spots.
I started with 3 of such accounts and will explain how to do this with a minimum of time to spend on these - we want to play with our main account.
Let's make some calculations: To benefit from concrete plant occupations two or three, in my opinion even 10 are not worth it. I want to have 1000 concrete per hour: 1 plant gives 114 every 4 hours or 28,5 per hour. 1000/28,5 = 35,08 so with a little round up i want 36 concrete plants and these need 180 population to operate them. As we need some shops and mines to get ressources and level up and warehouses to store them we have to go for level 50. By using shops this level can be reached in about four to five months by fetching the rewards three to four times a day.
In the end these plants give 36*28,5*24 = 24624 each day and 98496 concrete during a four day boss strike. Imagine i have three of such farms...
A long way to go? Not really when you only fetch rewards from shops and don't fight. This is possible, the faster way is to do some fights in the beginning up to level 10 or maximum level 15 against base invaders and critter for some gold. Above level 15 forget fighting on your base. Switch to fights in the arena - but only against drop formations and when you are in need of gold. To push this whole thing some artificial ponds to occupy will help a lot: The gold from these occupations pays almost all upgrades for buildings whre lumber is needed. Concentrate on shops, the mines don't need to be upgraded to more than level 6 until your are on level 45 - then all shops will bew at max level and if you have all the warehouses you want you can upgrade stone mines.
Warehouses: Build as much of the small warehouses as you have population to operate. Once at level 18 replace them with normal warehouses as fast as you can to free the population. At level 34 only build larege warehouses, but you can wait to replace the normal warehouses until you are around level 45.
Mills: Use all stone and iron spots and at least four for lumber. One for coal and oil is enough (if you can occupy for coal and oil).
Expansion: Expand, continously, every day when possible - we need space for our houses, warehouses and of course the concrete plants.
Gold: I used four refinement facilities to occupy - 4*3797/4*24 = 91128 gold per day or 2.5 million per month pays many of the expenses, even for three farms.
Houses: You can go for modern or modern duplex houses if you want, don't waste ressources in upgrading houses. I used camps and shelters and didn't upgrade them and rarely fetch the gold. Hovels and huts are not effective in my opinion.
Army: You need about 60 trooper for the occupations and let's say five tf2 soldier and three mini tank. That's all. You can replace the mini tank by some bigger, but this will not speed up battles much - only the heavier tank will be worth it when on level 47.
Population: There are two ways to get or free some people - Permits Office or High Capacity Vaults. I assume to have a Permits Office and level it up to level 3 in any case as soon as possible. So this is about what to do with the nanos from leveling up. Lets do some calculation: Leveling up the Permits Office to level 8 costs 550 nanopods and gives additional 25 population. Buying 4 High Capacity Vaults for the reduced rate of 98 each (why buy it at the normal rate, this is a long term project) you can free 32 population compared to the Large Warehouse for 392 nanopods. So this is an easy decision: Buy six High Capacity Vaults as the are available for the reduced rate - then you can get rid of all other warehouses and free the people.