Buying a man's suit isn't a question of simply buying a jacket, a pair of trousers and some shoes. It's about knowing where to buy a great suit, men's suit fashion styles and how your suit should fit you. Let Mr D give you the lowdown on how to buy a suit.

What is a suit for?

There's no easy answer to this question, since a great-fitting suit can do wonders for a man in many areas of his life:

• A suit makes you more than presentable in the office - it gives your mind a mental shift to help separate your work time from your party time.
• Women are drawn to confident men and a well-judged suit will give you confidence, whether you're conscious of it or not. 
• It ticks the boxes - I'm not much of a box-ticker myself, but there are times - at home, at work, at formal occasions like a wedding, whether you're delivering a speech or just a guest - where you'll need to wear a suit. So it's best you get one.

What sort of suit do I need?

Right, whether you go for a two-piece (a combination of jacket and trousers) or a three-piece (jacket, trousers and waistcoat), you're looking for:

1. Something seasonally appropriate - so that means a heavier-weight material for colder weather, say wool or tweed, or in summer, either linen or cotton.
2. Appropriate to where you'll be wearing it - a 'black tie' event calls for a dinner jacket (tuxedo), a social event a 'lounge suit' (essentially a suit which you tend not to wear to work) and a business suit for the office.
3. Something which you can feel comfortable in - it's a suit, not a straightjacket. You need to feel like yourself in it.

What should I look out for?

1. Jackets - should be lined - no-one wants to see the mechanics of your suit.
2. Sleeves - should stop at the wrist - enough to show your cuff-links and a degree of shirt cuff.
3. Trousers - length should rest at the top of your shoes - enough to hide your socks from view when standing, not so much that it gathers around your ankles.
4. The fit - this is why the size is so important. It should hug your shoulders without restricting your arm movement and crucially shouldn't pucker or gather awkwardly across your chest when the buttons are done up (never button up the lowest button, whether two, three or more buttons - this is also true of waistcoats).
5. Quality - avoid man-made fibres like polyester, it's not breathable. The sign of a good suit is in the detailing - if buttons and linings look cheap, you'll look cheap. Another sign to look for is in the jacket cuffs - are the buttons 'for show' or do they function? Ditto the quality of the lining finish inside.

How do I look after a suit?

• Avoid wearing jacket and trousers separately - why? Because they'll fade at different speeds and won't match when worn together.
• Hang it up - it's a tough one to remember after a big night out but a creased, crumpled suit will be your punishment if you forget.
• Get it dry-cleaned - the smells and stains of life will wear you and your suit down, so get it cleaned, regularly.

Where should I buy a suit?

You have one of two choices - off-the-peg or bespoke/tailored. If you can afford it, I would always recommend getting yours tailored. It will fit like a (stylish and comfortable) glove if you do, since no two men are the same.

In Asia, excellent tailors are still affordable. I use Sam's Tailor in Hong Kong, but you'll do well in buzz cities like Bangkok and Shanghai too. In western countries, off-the-peg is the norm, but they take their cues from high-end designer labels like Aquascutum, Hugo Boss and designers from London's Savile Row such as Ozwald Boateng.

So there you have it - everything you need to know about buying and owning a suit. But one final thing. Those labels stitched on to jacket cuffs with the brand name on them? You're meant to take them off once you've bought your suit. Never a trust a man who doesn't know that.