Being assertive is not the same as being aggressive and will, in fact, improve life for both you and your loved ones.
I believe that the ability to say yes or no when we really want to is a key life skill. Many of the people who come to therapy with me talk about times when they wished they had said what they wanted. For example, Mary the carer, who said she didn't need help with her mother from her siblings when they asked, despite being overwhelmed.
When communicating with other people, it helps to keep in mind not only what you are experiencing (thoughts, feelings, behaviours) but also what they might be experiencing, which might be similar, different, or completely opposite to your experience (and anywhere in-between!). Just because you believe they're thinking something about you, that doesn't necessarily make it true.
Find a good role model
It can help to think about a person who you respect and who you believe acts effectively and assertively, while respecting others and themselves, who is warm and friendly.
You can model yourself on that person – imagine them dealing with particular situations and then imagine yourself acting in a similar way– and then do it.
Practice it often
Initially, it doesn't matter if you don’t feel like being assertive, just practice it anyway. When you notice yourself acting aggressively or passively, take note of, then change your posture, expression and behaviour, as though you were being assertive. It works!
Seeing criticism as feedback
When we hear other people being critical of something we've done, we tend to believe that they are being critical of us, rather than our actions. This may be because we’ve been criticised in an unhelpful way in the past, which resulted in feeling blamed, rejected or unwanted.
However, the person offering criticism may intend the criticism to be helpful – pointing out the effect of our actions. If we were able to accept that criticism in that spirit, then we could make positive helpful changes.
We can learn ways of saying no that don’t lead us to think self-critically or feel guilty. For example: "I’m sorry but I really can’t take on anything else at the moment". Or "I’m quite busy right now. Perhaps another time." Or "I’d like to help you out, but I just don’t feel up to it at the moment."
If the person seems to have trouble accepting your 'No’, then just keep repeating yourself, over and over if necessary. You might have to emphasize the word 'No’, for example: "No. I'm sorry but I really can’t at the moment."
Imagine these answers like a card in your back pocket; with practice you can pull them out when you need them most.
Be wary of self-critical thoughts after you have exercised your new assertiveness. Practice challenging or dismissing them, by telling yourself: "I explained to them why I couldn’t do it." Or "It’s not my responsibility." Then put your focus on something else.
Telling others what we want
When we want something, we use all sorts of messages to try to let others know, such as hints, expressions and gestures. But the only way to ensure that someone has really understood what you want, is to be clear in what you say: "I’d like you to give me a hug." Or "I want to be your friend, but not your girlfriend."
When it comes to assertiveness, practice makes perfect. I am not a fan of perfect. Most perfectionists I know are anxious people. Not healthy. It's far better to observe in yourself the behaviours such as not being appropriately assertive and patiently start out on the road to change.