My idea along these lines, which I may have explained in this forum before, is to replace one of the houses of parliament (or congress, or whatever you call your local bicameral legislature) with the "House of Taxpayers", where representatives are elected by taxpayers whose vote counts in proportion to how much tax they pay. The other house remains a "House of Commons" where the one man/one vote rule applies.

The point of this idea is that every new piece of legislation must be approved (in effect) by two groups: the people who are affected by it (everybody) and the people who have to pay for it (disproportionately the rich).