HOW TO SAY NO
For some people, it is hard to say no to others but it is necessary to say no in order not to harm ourselves.
Here are some ways to show you how to do it without hurting others.
Try to have a strong tone of voice, without appearing harsh or intimidating. It should be obvious that you're not available, but that you appreciate the thought. Being firm shows you're not dismissing them needlessly.
This is the "thanks" in "no, thanks," and is the key to an inoffensive rejection. You'll want the person asking to know you're happy that they've thought of you, and you'd like them to continue thinking of you in the future.
Say it in person, if possible. Especially if it's something of significance, people appreciate a face-to-face meeting, particularly in this age of text messages and e-mails.
Kindness is key if turning down someone for an outing, or a date.
Keep it objective
Don't make it personal--making it personal is a definite way to offend someone, even if you don't mean to. Let them know you'd love to help them, but unfortunately, have no time for that. This helps to keep the conversation level-headed and unemotional.
For example, if someone asks you to help them move on the weekend, but you've already got plans, make it known that you don’t want to do that.
Know what you've said no to, and be mindful what you say "yes" to after the fact. Avoid seeming available to help someone else so soon after dismissing another. Whether the original person has all the facts or not, they make think you've brushed them off to help someone else.
The most important person in your life should be you and you alone, therefore, if something doesn’t make you happy or it makes you annoyed to try to avoid it even if you have to say no to someone. By considering the above points you could do it as easy as it may be.