I have a very small foyer, but I did this rug in a 4'x4' square and it looks really good. There is a kind of busy/modern rug in my office right off the foyer, so I needed something plain. This is tightly woven, rough so it is good for wiping feet on, but easy to clean. And affordable (I think it was around $50) so if it gets gross over a couple years I dont' feel bad replacing it. Rubber backed too, which is nice not to have a separate pad under it.
Some jute is great, some is no good for an entry mat. Just make sure the rug is plenty large enough for someone to step in and close the door (side to side and/or front to back) without stepping off. 4x4 was the smallest I thought would work (and takes up most of my little entry hall).
http://www.amazon.com/Natural-Fiber-Marble-Light-Gray/dp/B002XWCCTU/ref=sr_1_fkmr1_1?ie=UTF8&qid=1433266330&sr=8-1-fkmr1&keywords=safavieh+gray+square+jute