[dmethvin]

Dedicating your development time to a laundry list of "best practices" doesn't pay off that well. Measure where your web page is spending its time and fix that. Take image sprites for example. Setting them up takes extra steps and complexity in your build process and requires you to track which images you are using. With HTTP2 becoming common the cost of individual image requests isn't that bad.

[codedokode]

Usually most time is spent loading third party trackers, advertisement and social network widgets. You can "optimize" that only on client side by blocking them.

[imaginenore]

We iFramed them on one of the major websites I worked on. Didn't affect the revenue. And they render completely separately, don't block anything / cause layout thrashing.