When it comes to tensions headaches, I am not a newbie. I have all sorts of headaches (including the ones you'd get from coffee withdrawal) and, at times, I get migraines too.
With time I realized that the vast majority of all those headaches are actually caused by the trigger points I have in my neck and upper back muscles.
Here is a headache map you might find very useful.
The crosses represent the areas where trigger knots tend to develop whereas dotted red areas depict the referral pain pattern.
I was surprised to learn this but...
A lot of these knots develop as a result of NOT having a good elbow support so that the elbows are "in the air".
This is why you need to have an ergonomic chair or a desk that allows your elbows to rest on it.
Here is what a good setup looks like.
As you start having your elbows on a comfortable surface, your upper back muscles will stop overworking and create unnecessary strain.
And this is how you get less tension headaches!