Let's discuss optimization and split testing process

Howdy fellow affiliates. 30 min's ago I was split testing some ads/banners and I was wondering if there is a better way to do it than I'm doing it.

For example, I always start small (5 banners, 2 LPs, 2 offers or 1 offer with two different LP) when I start a campaign and go slow.

I brainstormed one hook/angle for a campaign and for that angle I got 5 different headlines for banners and 5 different images.
The thing is I started with 5 different images all with one headline. In short 5 banners that only have a different image, but same headlines, bodies and CTA's. Is it better this way and to see which image gets attention and conversion and than to split test the winning image with 5 different headlines and bodies later on, or do you do it differently? Like, use one image on 5 banners, but each banner different headline, so you know which approach/head gives you conversions and clicks so you can test only images later on? Which way is better in your opinion? How do you split test and optimize?

Similarly I do it with LP's. Lots of people talk about split testing and optimization, but not many talk about the strategies they use. I shared mine, feel free to share yours .