Pruning tomatoes, do you remove suckers or non flowering leaves?

[Kayemm]

There's so much conflicting advice. Last year I removed neither and had a jungle.

What do you do?

Not on the bush ones, but all the others you remove the little shoot that grows where the branch joins the main stem. Just pinch it out with your finger. You have to do it regularly as the plant grows and gets more branches, it doesn't take long to do. Keep the main stem growing up straight by winding it round string or a cane, and it's easy to see which bits to remove.
also as as they gets bigger it's a good idea to remove the lower branches to allow air to circulate round the bases and help prevent disease.

I only remove shoots growing where a leaf meets the main stem.
I’ve never had ‘suckers’.
I’m not sure what you mean by ‘non flowering’ leaves?

I second @FizzingAda's advice. When the plants are getting taller and bushier, I'm pretty ruthless in removing any branches that are interfering with the tomatoes or too close to the ground in order to allow for good air circulation. They only need a certain amount of sun leaves. I also fairly regularly check for side shoots to make sure I keep only one (or at the most two) main stems. You have to keep on top of this as they grow quite quickly!