To expand on our great democracy, we should be able to vote by any means available, including by mobile phones. If we can bank by mobile phone, we can vote as well. Enabling mobile voting would raise voter turnout up to 90%+ instead of the current 40%-60%. Really, more government services should be accessible online.
Ideally there would be no more politicians. Nobody likes politicians, and nobody wants to run for office. We can protect ourselves against corrupt politicians using a process called sortition, where laws are created through a jury of your peers instead of through politicians. Random citizens would be selected to become our legislators, similar to jury duty. This was how democracy was originally done by the Greeks.
It should also be easier to remove politicians. Impeachment used to happen all the time, now it's seen as a gravely serious act. There's no reason for that, and it should be normalized.
We could also hold constitutional conventions every decade. We should implement full court reform through more specialized courts, as well as separating judge selection from the legislative branch.