One of the luxuries of shopping at tailors and other high-end menswear stores is the knowledge of staff. OK so if you’re a real shoe geek you might know more than the sales assistant – few people care what a rand is, even if they love shoes. But that assistant will at least be able to explain the different lasts on offer, give you decent advice about sizing and know the difference between an Oxford and a Derby. In short, they will know their stock.

What a shock it is to return to the high street. Inspired by a recent post by my friend Steven Taffel, owner of Leffot shoe store in New York, I went in to Uniqlo yesterday to try its jeans.

If I could help it, I’d rather not pay too much for jeans. As long as they are reasonably well made and won’t fall apart, the only thing I care about is fit. And Steven’s seemed to fit pretty well.

As regular readers will be bored of hearing by now, I have large thighs and a small waist, so buying trousers off-the-peg has always been hard. I recently realised, though, that my tailor can take in jeans at the waist – as long as I’m not that bothered if the thread doesn’t match exactly.

So, all I needed were jeans that fitted in a straight, narrow line and could make it over my thighs. The waist was irrelevant. The good news is, Uniqlo had some. The bad news: it took me half an hour to find them.

Having tried on both slim and regular fits in a few sizes, I was puzzled that the width of the leg (at least below the knee) didn’t vary between styles. I asked one of the sales staff. Blank look. Are the regular jeans more tapered below the knee? Nothing.

OK, this was probably expecting a little too much. These guys didn’t design the jeans after all, they’re just selling them. So I asked whether the blue selvedge jeans (there were two colours, blue and black) only came in slim fit, which appeared to be the case from the table display. No response. “Are these just in slim fit?” I asked. That produced the worst possible response – the assistant started looking at the labels.

If you have to check your own stock to work out what’s there, what use are you? You’re just doing what I’ve been doing for the past 10 minutes. But slower, and with less enthusiasm.

So I took a logical approach, taking two sizes in each of the two styles in three different ranges. Twelve pairs of jeans.

Next time you’re in Uniqlo I recommend asking a fellow shopper for help rather than a sales assistant. They’re likely to know more and be more inclined to help.