Anything that lessons the tax burden for small / sole prop. businesses (don't forget they have to pay Nat Ins contributions for employees too). They may even be able to afford an employee or two then.What about a more progressive tax system where the smaller companies pay less and taxes on profits are tiered. I definitely agree with reducing tax on smaller business, but bigger companies would just use it to fatten the wallets of already wealthy people.
For large businesses how about a tax break if they reinvest showing that they increase plant and personnel (obviously there would be a need for high vigilance to prevent misuse of funds) again it could lead to increased business, profits and bonuses (and higher employment) as owners/investors aren't going to invest funds without the likelihood of further lining their pockets, nature of the beast.
Whatever I really believe a tax overhaul is necessary to incentivise. Without it, as Dantes said, they'd be better off investing it in bonds/shares.