A sleeve that covers your hand or a waistband that gaps can keep an otherwise useful garment in the wardrobe. Before replacing it, ask a tailor what can change and what the work will cost.
Describe what happens when you move
Wear the piece for a few minutes before the fitting. Sit down, walk and reach forward. Notice where it pulls, rides up or gets in the way. That is more useful information than saying it does not look right.
Bring the shoes and layers you normally wear with it. A trouser hem pinned over trainers may sit differently over boots. A jacket fitted over a thin T-shirt may not leave enough room for your usual jumper.
Ask what the construction allows
Letting a garment out depends on the fabric left inside its seams. Moving a shoulder, changing the rise of trousers or working around pockets can involve more than the visible adjustment suggests. Ask the tailor to explain the limits and quote before cutting.
Keep the intended shape in mind. A loose coat may only need shorter sleeves. Trying to turn it into a fitted jacket can change the balance and cost more than you expect.
Check the result before leaving
Try the finished piece on with the same shoes and layers. Move as you did at the first fitting. Check that a new hem sits evenly and that sleeves still allow you to reach forward.
Ask for spare buttons and any useful offcuts to be returned. Keep the repair receipt with a note of what changed. It can help at the next appointment, though a different garment will still need its own fitting.
