#LightningStrikes  The Lightning App Builder is a wonderful thing but over-use can confuse users. Before you customise every single page to be different consider the impacts on user training and familiarity. I try and group pages by user experience and have a common layout and default tabs that minimise clicks, but are consistent. Here's 4 more of my personal top tips:

1. Decide whether your tabs are going to be alphabetically ordered, or by frequency of use. Stick to the same system across ALL pages!
2. For more static data based pages such as Account and Contact you probably want the Related Lists to be visible by default. Related List Quick Links are a wonderful way to reach these quickly.
3. For transactional data pages such as Lead, Case, Order and Opportunity you're more likely to interact with the Details tab and the Path. You almost certainly want some details of the Account and/or Contact there on the page too so try and be consistent where you place your Related Record component
4. When using different Pages per App or Record Type think very carefully about whether you really need to create (and maintain) the different pages, or whether you simply need to use the Component Visibility to hide components instead.