I have been doing something silly recently - applying for credit cards. Previously, I only had one plastic, which is a supplementary card given by my father, the POSB Everyday card.
My "crisis" occurred recently when I started traveling overseas for holidays and for work. The expenses that were charged on the card was within limits, but it affected my savings because say in June when I had booked a hotel, I only paid up in July or even later because the bills were overlooked (but were paid due to GIRO deduction) as they were not addressed to me. Now that I have got myself a personal card, I hope I can bring my spending and saving into a balance (more savings definitely!).
The lessons learnt here are simple. Always set aside money to pay off credit card bills. And while it may be convenient to have and use a credit card, you tend to overspend because you do not feel the pain immediately and it screws up your mental accounting. Therefore, unless you are going overseas or trying to impress your date, you should leave your credit card at home. That way, you will not overspend your month's budget.