Scaling an agency requires a very different set of skills and strategies than starting an Adwords agency. Here are 5 strategies to help your Adwords agency scale:
Pareto's 80/20 rule is an underpinning philosophy in all this.
At all times, keep in mind the potential ROI gain of what you're trying to do in function of the cost in time and also future complexity. Maybe you should restructure the whole account with only SKAGs and negatives at every entity level to isolate traffic. Think again. That's far too hard to maintain, it's just not worth it. Maybe you should have 1 Adwords account per targeted country, then have each campaign target a city? Definitely not.
Simplicity is your ticket to future action.
Adgroup level bids
As an example of 80/20, what if you just decided to enforce adgroup level bids, and never do KW level bids. That would remove a tremendous amount of complexity, and easily get you 80% of the control you need, especially if you've got a tightly structured account (small, themed adgroups and SKAGs). It also helps with aggregating data to make decisions.
Processes and automation
About those decisions! Create a code of conduct so that you don't have to gut feel everything every time. Classics are CPA decisions:
For example, pause adgroups that have no conversions and where cost > 3x target CPA.
Opteo has got most of this part covered for you -- smart rules that you can rely on.
Account wide ad tests
I'm a fan of testing ad creatives account wide (eg. Testing headline 2a vs. headline 2b across all or many campaigns) using labels to aggregate the data. A small amount of effort to generate a new headline can be leveraged across your whole account. Basically, you can hugely speed up ad testing. Sure, you can make the argument that each adgroup should test for a better ad specific to that adgroup (which is probably true for high volume adgroups), but account wide tests win via simplicity and speed of testing. (This isn't yet something you can do with Opteo, but hopefully one day soon!)
Weekly focuses/workshops that feed into reports
I learned this method from Ricky, one of the founders behind PushGroup (a ridiculously fast growing agency in the UK). Here's what they do: every week, they have themed 'workshops'. For example, a week's theme might be 'Ad extensions'. All the account managers get together for a half day and focus their attention towards ad extensions across all their accounts. Suddenly everyone is living and breathing ad extensions, sharing strategies, digging up blog posts about ad extensions for inspiration etc. Say the following 3 workshops are: 2) Testing DKI in ads across the whole account, 3) N-Gram analyses of Search Query Reports and 4) Single Keyword AdGroups.
At the end of the month report, there's no confusion as to what was done on the account this month "Hi ClientFirstName, this month, we've taken a deep dive on your ad extensions, tested DKI in ads across your whole account, analyzed your search queries and created SKAGs."
Talk about batching tasks and aiming for simplicity and repeatability. Hats off.
tldr; simplicity and automation are keys to scaling your agency. Work smarter, not harder.