Is there another way of saying, "broken in?"

Worn-in, according to Wiktionary:

(of clothing) More comfortable as a result of having been worn often or for an extended period.

From the phrasal verb to wear in, according to Collins Dictionary:

if you wear in something such as a pair of shoes, you wear them until they fit your feet better and are more comfortable

Real-world examples

In reply to Mitch's comment, I have searched for real-world examples of this use as an adjective, I have found some on the Outdoors SE:

But with well worn-in boots I always tend to get more blisters if I wear only one pair. source

Make sure you have proper hiking boots, which fit you well, and which are well worn in. source

Attribution:

1 "Worn-in." Servent - Wiktionary. Accessed May 10, 2018. https://en.wiktionary.org/wiki/worn-in.

2 "Wear in (phrasal Verb) Definition and Synonyms | Macmillan Dictionary." Grassroots (adjective) American English Definition and Synonyms | Macmillan Dictionary. Accessed May 10, 2018. https://www.macmillandictionary.com/dictionary/british/wear-in.

3 Aim Kai. "Is It Better to Wear One Pair or Two Pairs of Socks While Hiking?" The Great Outdoors Stack Exchange. Accessed May 11, 2018. https://outdoors.stackexchange.com/q/1013/8227.

4 Fgysin. "How to Get Prepared for Fjällräven Classic Hiking Tour?" The Great Outdoors Stack Exchange. Accessed May 11, 2018. https://outdoors.stackexchange.com/a/13434/8227.

Seasoned. Implying fully ready to use (consume) and having passed enough time to be found useful and satisfactory.

I’d suggest well-worn.

The OED defines it as:

well-worn

Much worn or used; showing the signs of extensive use or wear.