Even the casual closet can benefit from a good tailor

All wardrobes, no matter how luxe or stylish, can benefit from a good tailor. Or so sayeth Tim Gunn.

Gunn, "Project Runway" mentor and currently fashion's favorite father figure, is an evangelist for the wonders a tailor can work when it comes to making clothing more flattering.

Tailors and seamstresses have long been relied upon to fix formalwear. But even though they're an extra step and an extra expense, don't discount them for your everyday wardrobe, too. They can quickly and easily fix too-long sleeves and pant legs, take in waists that are too large and generally nip and tuck at clothes to make them look better on your body.

Here are 11 things you need to know before you walk into a tailor shop with a closetful of clothes:

1. If you plan to have a garment tailored, buy the size that is too large, because taking in a garment is easier than letting it out. Also, look for the size that fits your largest body part. Jeans, for example, should fit the thighs and bottom, even if they're too big in the waist. Blazers should fit across the bust, belly or shoulders — whichever measurement is biggest.

2. When choosing a tailor, ask for referrals. A well-established tailor will have customers who can provide references.

3. When having jeans hemmed, ask the tailor to "keep original." This means they'll shorten the legs but keep the original hem. Otherwise, the tailor might simply turn the jeans under and hem them like a pair of slacks, which looks dated.

4. Tell the tailor about any variations in your body, such as a curve in the spine or different leg lengths.

5. Communicate clearly and precisely. "Hem these pants" might mean, "fix them so that they're just above the floor" to one tailor and "fix them so they sit at the top of my ankle" to another. Finding a tailor who will learn your likes and dislikes, and appreciate your personal style, is paramount.

6. A good tailor can do more than just sew. He or she should understand fit and be able to suggest design changes that will make clothes look better.

7. Buy the most expensive clothing you can and choose classic styles, especially with garments such as suits. More-expensive clothing is usually easier to tailor because it has more fabric in the seam and the fabric is of higher quality. This often means the garment can be tailored or restyled more than once.

8. Consider using a tailor for thrift-store purchases. A classic, well-made garment can be updated for a better fit and more modern style. You might spend $200 altering a Chanel suit from the '80s or a Dolce & Gabbana dress, but in the end, you will have still gotten a bargain.

9. Be realistic about what to take to the tailor. Can a tailor fix a pair of pants that are four sizes too big? Yes. Is it practical and cost-efficient? Probably not, unless they have special significance. Also: Fixing shoulders is one of the most expensive and time-consuming alterations.

10. Think about proportions. Yes, a tailor can shorten sleeves that are too long. But if the shirt hangs down to the knees and the pocket is so low it is almost to the belly button, the shirt will require major reworking, even if fits around the collar. Ditto with suit jackets.

11. Know basic fit guidelines. Men should be able to just grasp the bottom of suit jackets with their fingertips at their sides, and the jacket should just cover the seat. Women's skirts should fall just above, right at or just below the knee. Shirts should fit through the chest and waist.