1. In Taobao.com or any Chinese online website, the sales would probably say “我家衣服的质量最好。” (colloquial and casual ). But, you could also say “我卖的衣服质量最好。” (卖:sell) if you’re selling clothes. Or still, you could say “我的衣服质量最好。” if you’re talking about your clothes with your closed friends. (的 should be put in a right place.).
2. 质量好 /高质量/ 质量最好/ 质量不太好