But how does it happen?
Often this sort of thing creeps up on you, you're already a clone by the time you notice. If you are happy with this arrangement, the loss of your own identity in favour of a group identity, it could show an underlying lack of self-appreciation.
Is it really a problem?
Some similarities between you and your mates are natural, and quite possibly what brought you together in the first place. Where the problem develops is when you realise all that you are has been blended and blurred and spread across your close friends. While we need friendships, we also need to be fulfilled within ourselves. Giving up your individuality will eventually come back to haunt you; you will end up feeling anger, resentment, and/or regret. You may even take it out on your mates.
If they're copying you
This is a form of flattery, and while you may not appreciate this, they are simply showing that they admire you and your style. It also suggests that your friend has low self-esteem, so perhaps the best way to remedy the situation is to help them feel better about themselves and take them out to help choose their own style.
How do I keep my individuality?
Assert yourself; if you are fed up with the way your friendships are going, say so. If the cloning irritates you too much, or their company bores you it may be worth thinking about finding some new friends, however it may be that all you need is an honest chat to resolve any issues.
You need to maintain other hobbies and interests. Don't give these up for the sake of your friendship, they make you you, and without keeping up your own life you won't have much to offer to your friends. Write a list of all the things in life that you enjoy, no matter how trivial they might seem at first. Now plan to do at least one small thing every day, and have bigger things to look forward to as well.
Maintain other friendships/ make new friends. Spend time with a wider variety of people, this way you won't get stuck in a friendship rut, and you will avoid cloning by being with different groups.
You have to have your own personal goals and set out to achieve them. Stay interested in life and the world around you, if you manage to step outside your little friendship bubble every so often, it will be easier to avoid getting clamped down and zapped of your spirit.
Compromise. Note the difference between remaining unique, and just being stubborn. Just because you want to remain individual doesn't mean you have to do everything your way all the time, you need to be able to compromise with your mates, or you'll risk losing them.
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