You can use a complimentary color and material that fits in with the rest of the furniture in the grouping. An ottoman can serve as a coffee table for drinks and snacks and a surface for your laptop. A dark leather could work. Have to see all the other pieces.

An ottoman just for that chair? If so - then it should match or compliment.

What does the sofa look like?

you could try some smaller scale options in a complementary pattern

It does not need to match at all! But you have to give us more to go on......

What else is in the room? A rug? A couch? anything? Got pics of the room? Post them below. We'll assume there are other things? Even if this is in............a bedroom? A living room? A study?

https://www.houzz.com/discussions/6411000/how-to-houzz-how-to-ask-questions-how-to-get-helpful-answers-and-e#28784466

We need to see the space it is going into .Right now we have not enough info to answer .

The ottoman should go with your current design and decor items. Here is just one design we did with ottomans:

Wine Country Charm · More Info