A key part of being able to be assertive is being able to be vulnerable.
Things like giving compliments and being able to take criticism are so difficult, but key skills of assertiveness because they force you to be vulnerable.

Resist the urge to respond to a compliment with a compliment - that’s throwing the complimen back in the person’s face. Accept it graciously and if you want to give others a compliment, make it something specific so they know you mean it!

When giving it make sure you are specific, and make sure you are criticising their behavior not the person. Only mention one thing at a time and give the person a chance to reply. If you receive some criticism, listen and be open. Make sure you understand what is being said before you jump to conclusions. Decide if the criticism is valid, and if it is say what you plan to do. Always say thank you for constructive criticism, it’s what helps build us into better people!

If you are passive, you may believe your needs are not as important as others, and therefore end up putting others first a lot of the time. That is not necessarily a bad thing, but it is if you end up burying your own feelings and avoiding confrontation at all costs.

Aggressive: If you have felt previously ignored or not heard, you may have ended up communicating aggressively by default. You may think being aggressive is just worse for others,as it can make you interrupt people and push things to prove a point, but it has a damaging effect on you too. It’s not an effective way to get your needs met and very few people respond well to aggression.

Passive: A lot of people communicate passive-aggressively (think eye-rolling, face-making, and blaming others for their hardships).

Ask yourself, what are you currently tolerating? Saying ‘no’ is an assertive quality that a lot of people find hard. Remember that if you feel anxious about saying ‘no’, you can tell them this and sometimes it really helps.

You also don’t owe anyone an explanation. You have every right to say no.
Once that person has accepted your ‘no’, and not before, you can compromise with them. Don’t forget, you can ask for time to think and even change your mind. Just don’t say “I’ll think about it” or “Maybe…” when you mean “no.”

It’ll make it easier to assert your strengths if you silence your self-critic and step away from social expectations by approaching yourself as you would someone else. Think about what you’d tell a friend if she told you that she’d been working in her job for ten years, knew others who has been given pay rises, but was too scared to ask for one. You’d be telling her to march in there and demand one! So why not tell yourself the same? Everyone deserves to be happy. And your needs are just as important as everyone else’s.

We have a tendency to apologise after we say something we mean. But if you don’ believe what you’re saying, why should anyone else? It can be hard to conjure confidence if you have little, but the ‘fake it till you make it’ method works well. Stop mumbling, apologising and prevaricating.

Asking for what you want, whether it’s a pay rise, a more reciprocal relationship, or your order at a restaurant, can leave people feeling anxious. And it boils down to this: you don’t think you deserve what you are asking for. Ask for what you want. And decide what you will do if the answer is no. The key is to be specific. It’s a lot easier to say no to someone who says “I think I deserve a pay rise” than someone who says “I have been here for 10 years and I work really hard. I would like a £5,000 pay rise next year”.

Confidence is key to assertiveness, so celebrate things daily, even if it’s just getting out of bed and getting dressed. Assertiveness is directly linked to confidence and self-esteem. Think about the areas of your life that you struggle to be assertive in – work, relationships, customer service – those are the areas where you feel most insecure and therefore should focus on.

Contrary to popular belief, being aggressive and being assertive are not the same thing. People who are assertive believe that their needs are just as important as others, but not more important as someone who is aggressive might think. They are confident, direct, and can express their thoughts, opinions, and feelings honestly. Stop fearing disapproval.

Crippling self-doubt can cause us to stop us raising our hands in class, make us unable to ask for a promotion at work or stand up to someone in a debate. Until you achieve genuine self-belief and confidence, try faking it and it may just develop naturally.

Further reading:
How To Be Assertive In Any Situation – by Sue Hadfield and Gill Hasson.
The Assertiveness Workbook - by Randy J. Paterson
Girl Up – by Laura Bates.