As a business owner you can claim allowable business expenses for:
advertising in magazines, newspapers etc.
direct mail/leaflets
bus advertising
facebook ads
google ads
radio ads
remarketing
vehicle signage
website costs
trade journals
professional organisations eg. FSB
You cannot claim for:
entertaining
hospitality
gym memberships
payments to political parties
donations to charity, but you may be able to pay for sponsorships
There may be variations depending if you are a sole trader or limited company.
Always check with your accountant.