If,as seems likely, David Cameron is elected Leader of the Opposition he has three years to devise an agenda. Hurrying would be unwise. Those three years will seem the a change in Prime Minister and in some government policy.
Putting a strong team in place is the first step. It is not necessary to grant every shadow cabinent member a portfolio - it would be wiser to allow at least a few the liberty to speak across a range of issues. Churchill allocated no portfolios to his shadow cabinet. Margaret Thatcher allowed wide-ranging debate. It was Michael Foot - the least successful opposition leader ever, who led his party to a net loss of 60 seats - who introduced the idea of shadowing every minister.
Apparently Kenneth Clarke has intimated that he might possibly deign to serve under another leader. This would be good. He is a man of considerable talent. He has only one speech - about how much better everything was when he was Chancellor - but he delivers it well, and it goes down well with the small and diminishing group of people who voted Conservative in 1997. These are people he can rally, leaving the Leader to focus on reaching out to new people. Clarke would be an effective Party Chairman.
I would love to see Oliver Letwin return to shadowing the Home Office. If David Davis ever wants to have another chance at the leadership he needs to effectively shadow Gordon Brown. No doubt William Hague will return to front bench politics.
This will be an effective nucleus, but it is a long way to go.