I am using this kind of method too and it is really an effective way to save money. 
Whenever I want to buy something my friend will contradict everything I'll say. 
He makes me realize that I should be wise in spending and that it is'nt easy to earn. You should give it a try. Try to monitor your expenses too.
Awwwts. That was sad, I never knew that one of your friends saves money for you. I think the "friend" you were talking about is your boyfriend. Because he's the only one I knew who saved your money. But in this posts of yours. You said that it was your friend. You can't even mention your boyfriend. That feels so sad. I hope he didn't see this post. It will really make him so sad. You know, he's really grouchy. Whenever I want to buy something my friend will contradict everything I'll say. He makes me realize that I should be wise in spending and that it is'nt easy to earn. You should give it a try. Try to monitor your expenses too.My formula on saving money is (income - savings = expenses) you can put the 25% of your income to your bank account. That's the best tip for me to save money.
That is a good idea. Saving 25% of your income to bank will really save money. By the way, do you save money to bank every week or everyday? But I guess its every month isn't? But, let me give you some tip. Besides from saving your money to bank, why don't you try to invest some of your income to bitcoin when bitcoin's price is down. In this way, you saved money you also earn money when you sell it when bitcoin's price go back up again.