Start With the Right Fit Foundation
The single most important rule in selecting a garment for alteration is to ensure it fits the shoulders perfectly. The shoulder area is the most complex, costly, and difficult part of a garment to change. An ill-fitting shoulder can disrupt the entire
balance, drape, and silhouette of a piece, a flaw that no amount of other tailoring can truly fix. If the shoulders don't sit right from the start, it's best to walk away. Beyond that, a garment should already be a reasonable match for your size. Generally, taking a garment in by one or two sizes is feasible. Letting it out, however, is a different story. It depends entirely on the amount of extra fabric, known as seam allowance, hidden inside the seams. High-quality clothing often includes generous allowances, sometimes up to two inches, while fast-fashion items may have very little, making them impossible to enlarge.
The Green Light: Simple and Practical Alterations
Many common fit issues are straightforward and relatively inexpensive for a tailor to fix. Hemming trousers or skirts to the correct length is one of the most basic and impactful alterations. Likewise, shortening sleeves on shirts and jackets is usually a simple job, provided there are no complex details like functional buttons at the cuff. Taking in the waist and side seams of trousers, skirts, and some dresses is also a very common and effective adjustment. This can eliminate gaping at the back of a waistband or remove excess fabric for a more defined shape. Tapering a trouser leg for a slimmer silhouette is another highly achievable alteration that can significantly modernise a pair of pants. These types of changes work with the garment's existing structure to refine the fit without redesigning it.
The Yellow Light: Complex but Possible Changes
Some alterations are possible but require more skill, time, and budget. For example, while shortening simple sleeves is easy, shortening a jacket sleeve with functional buttons is a complex job that may involve detaching the sleeve at the shoulder. Adjusting the rise of trousers—the distance from the waistband to the crotch—can be tricky because it affects how the pants sit on your body and can require significant reconstruction. Taking in a lined jacket or coat is also more labour-intensive, as the tailor must open and then reconstruct the lining. While these alterations can be done, their cost can sometimes approach the price of the garment itself, so it's essential to get a quote and decide if the investment is worthwhile. These are jobs for an experienced professional, not a quick fix.
The Red Flags: When to Walk Away
Certain alterations are structurally impractical or impossible without fundamentally remaking the garment. As mentioned, significantly changing the shoulder width of a jacket or coat is a major red flag. Attempting to resize a garment by more than two sizes is generally not recommended, as it distorts the proportions of darts, pockets, and other design elements. You cannot make a size Large shirt fit like a Small without it looking unbalanced. Letting out a garment that has no extra fabric in the seams is another dead end. Materials like leather, suede, or heavily beaded fabrics are also extremely difficult to work with; every needle mark on leather is permanent, making adjustments risky. Finally, design features like zippers, pockets, or intricate panels usually can't be moved without ruining the garment's appearance and function.
Your Measurement Toolkit
To make informed decisions, you need accurate measurements. Use a soft tailor's tape measure for best results. The most crucial measurements for tops and jackets are the chest (around the fullest part), shoulder width (from the edge of one shoulder to the other across your back), and sleeve length (from the shoulder seam to your wrist). For trousers and skirts, you'll need your waist (at your natural waistline), hips (around the fullest part), and inseam (from the crotch to your desired hem length). When you're in the store, bring your tape measure. Comparing your body measurements to the garment's measurements will give you a clear idea of how much work is needed and whether the changes fall into the green, yellow, or red light categories.














