My tips are:
Don’t auto-renew any contracts, shop around or haggle with your supplier for a better deal (eg insurances, software, maintenance contracts, even bank accounts and phones)
Don’t tie yourself up in long-term agreements, make sure you are clear about the terms and conditions including any get-out clauses or cancellation penalties.
Make sure you know what your employees are spending on your behalf, it is not unheard of for employees to defraud their employers!
Revenues have to exceed costs, else you have no business, keep regular records tracking costs and income and updated cashflow forecasts with bank reconciliations, if you can’t do this by yourself, then seek assistance from a proactive Accountant (such as myself)