It depends on the ironing board. My metal one has 'dips' in it where the metal supports are and therefore doesn't give a smooth ironing surface. I had my DH put together a couple of bedroom end tables, separated enough to fit a chair between, and laid a board over them. Made my own padding (you'll need several layers) and covered it in some upholstery fabric that goes well with our living room. I like ironing on the smooth surface much more than I liked ironing on the store bought ironing board. When my 'grands' are visiting, the iron is put away and a computer sits on it so that I can monitor their use of it.
I use this set up because my fibromyalgia and arthritis sometimes flare so that I can't stand very long. It's working out well for me.
You could just attach a board to the top of your ironing board and cover it to get a straight surface. We were going to do that, but this looks much better.