Our constitution could use a bit of an overhaul. There are a few amendments I could foresee the utility of, however.
Congressional Compensation
Sec. 1. The XXVII article of amendment to the constitution is hereby repealed.
Sec. 2. No law, varying the compensation for the services of senators and representatives, shall take effect for at least ten years.
Sec. 3. Senators and representatives shall receive a salary, paid out of the Treasury; as well as a compensation for expenses to be strictly monitored by the Treasury, and cash salary for serving as officers and on committees of either house. But no senator or representative shall receive any other emolument or salary other than the aforementioned cash salary.
(affects 27th Amendment; and Art. I, Sec. 6, cl. 1)
Gerrymandering
I wouldn't know how to word this one. But prohibit the "enumeration" of representatives by political or politically-related authorities by the state governments after each national census.
(affects Art. 1, Sec. 2, cl. 3)
Limits on bills--content
All bills must relate to but one subject, to be expressed in the title, and all amendments thereto must be germane.
A lot of states have this, Maryland included. Typically, our bills do not exceed 50 pp I understand.
Any other thoughts?