Reputable places in the UK to buy Sunday merch

I’d really love to buy a t shirt for the Sundays, but cannot find any places that aren’t Temu, SHEIN, printerval, or redbubble to get good quality t shirts. Etsy has some but they are hit and miss. A lot of the time t shirts from Etsy are printed poorly and make the t shirt fall on you very badly. I’d love to know if anyone has any ideas!