When you're doing the tea or coffee dyeing and want the more antique look, I dipped the towels in the tea for about 1/2 hr, rinsed and allowed to dry. After the towels were dry, I took a clean 2" paint brush dipped in the tea and dab on a paper towel to take up the excess liquid then brushed tea over the towel. Allowed the towel to air dry. This gave a more stained appearance instead of overall aged appearance.
Something that I found with the tea, and maybe this might depend on what type of tea is used, but I used ordinary tea bag tea but the tea-dyed towels had a pinkish cast to them where those dyed with coffee had more of brownish shade. My husband says when he was a Boy Scout, his grandmother dipped his BS shirts in strong coffee to help keep the khaki color. Chris