<title>Cheap Car Insurance</title>
<h1>Cheap Car Insurance</h1>
<title>Compare Cheap Car Insurance Online</title>
<h1>How To Get Cheaper Car Insurance</h1>
Just have your main keyword somewhere in there and make it look natural. In my opinion, your title should have the keyword exactly how it is, and the H1 can be some sort of LSI.
For example, if your main KW is "cheap blue widgets", have it like that in your title, but your H1 should be something like "Blue widgets for cheap". This way it's less likely for it to be considered as spam/over-optimization.