I had a bad first experience at Raymond's and will not go back - disappointing, since they are close by. But others have had good luck there, so I'd still tell others to give them a try...but start with an easy inexpensive repair (inexpensive clothing). They kinda ruined a pair of brand new chinos, although I bought them at an outlet, so my loss was small.
There are other folks in the nabe who've gotten good reviews, but I've not tried them. One is a tiny storefront in the low 80s (sorry, I forget the exact block), just south of Roosevelt (west side of the block). Easy to spot if you walk there - just a tiny room off the street with lots of clothes and a sewing machine. Supposedly cheap and very good.
A little more pricey and further away but excellent in my experience is this guy who works out of his home in Astoria. Not a far walk off the Q/N line. Yelp reviews explain you need to call him, etc. but in my experience, going there about half a dozen times, he was very reliable about meeting times, completion dates and easy to connect with. His work was super professional quality. For a nice quality suit you want done right, I'd go there. I've paid two-three times as much in Brooklyn and four times the $ in Manhattan and his work was better than theirs imo.
https://www.yelp.com/biz/jimmy-the-tailor-astoria