I went into Leeds yesterday and jesus christ it was unbelievably busy, bloody students lol.
For the trend concious I recommend the obvious trip to Burtons, Topman, Envy and River Island. Also take a look in Muji for a more formal look or upstairs in Burtons, or Route 1 for skate-casual. Then you've got Diesel, Boss, Reiss, All Saints and Size? down in the Arcades which are quite expensive but decent, it's all up to you.
The Leeds Vivienne Westwood store is the bo-shizznat.
*n
What's Eid? Just googled it and it gave me "islamic festival", is that correct?
As for the clothing, H&M's winter collection has some pretty sharp looking tailored peices. Winter jackets, knitwear, tops etc. Also give Zara a go. If your into the less formal and more casual, try river island or topman.