1. Don't launch a website with spelling and grammar mistakes.  You will immediately alienate a large section of your audience and all those online marketing dollars will be wasted.

2. Don't wait days to respond to a new business inquiry – your chances of success will go down with every hour that ticks by.

3. Don't pitch a company before you've checked out their website – that is a sure sign of an unprofessional salesperson.

4. Don't accept requests on LinkedIn if there's a doubt about authenticity.

5. Don't send a LinkedIn invite to someone high profile, or someone it's important you connect with, without a personal note to explain the reason for your contact.

6. Don't connect on Facebook with prospects in business you barely know - connect on LinkedIn instead.

7. Don't use free machine translation software to email contacts in another language - it's only 70% or so accurate and could convey an unintended or offensive message.

8. Don't scrunch up business cards in your back pocket – Asian businesspeople will particularly be very insulted.

9. Don't write on business cards.

10. Don't pick up calls during client meetings except for emergencies – if you’ve scheduled a meeting with someone, they deserve your full attention.

11. Don't use "millennial speak" to interact with people of older generations – that will result in an automatic disconnect. 

12. Don't criticise people or businesses on social media without getting your facts 100% straight - or you'll look like the fool later.

13. Don't bring up politics in a meeting unless you're sure of the other side's views.

14. Don't proselytize religion in business forums. 

15. Don't get a reputation for always being late - doing things when you promise builds trust.

16. Don't make swear words a feature of your meetings.

17. Don't send emails without quickly skimming for typos.

18. Don't just leave a voicemail for a potential client - send an email as well, with your full contact details, to save the other party writing down all your details, and to give them the option of just clicking "reply".

19. Don't make your first interaction with a prospect an email telling them to call you. Ask a convenient time and do the chasing yourself!

20. Don't guess how to pronounce a foreign client's name - ask politely for the correct pronunciation to avoid embarrassment.

Connect with consultants to help make your business a success – just select a category.