Petra Voss has been altering and tailoring for over twenty years. She works from the back studio at Velvet River Trail every Tuesday and Thursday. This is her practical guide to the alterations that make the most difference to how a piece wears.

Hems are almost always worth it

A hem alteration is the most straightforward thing a seamstress does and the one with the highest return. A trouser that is two centimetres too long will never look right, no matter how good the cut. A dress that hits at the wrong point on the knee changes the whole proportion of an outfit. Hemming is quick, relatively inexpensive, and the difference is immediate. If you are hesitating over a piece because the length is not quite right, it is almost always worth doing.

Taking in a jacket or coat

This is more involved than a hem but often worth it for a piece you love. The key question is whether the shoulders fit. If the shoulder seam sits in the right place, most other adjustments are possible. If the shoulders are wrong, taking in the body will not fix the overall shape. Petra will tell you honestly whether a jacket is worth altering before she starts. She has turned down work before because the piece was not worth the cost of the alteration.

Replacing a zip

A broken zip is one of the most common reasons people stop wearing something they otherwise love. Replacing it is usually straightforward and costs between £25 and £45 depending on the length and type of zip. Invisible zips in a dress seam take longer than a standard zip in a jacket. Bring the piece in and Petra will give you a quote before you commit.

What is not worth altering

Petra is direct about this. If the fabric has degraded, if the construction is poor, or if the alteration would cost more than the piece is worth, she will say so. She has a particular view on cheap fast-fashion pieces: the fabric and construction often cannot hold an alteration well, and the result is a piece that looks altered rather than fitted. Her time is better spent on pieces that will reward the work.

Petra is in the studio every Tuesday and Thursday. Book through us by calling +44 1962 774 203 or emailing hello@velvetrivertrail.com. Alterations start from £25.