I have a affinity for Chinese martial practices that are not form based. I like push hands and I will forever be in love with the practice ideas and methodologies of Wing Chun, also spelled Vin Tsun. Part of the Wing Chun practice program involves working with the famed wooden dummy. I made one a while back to practice and flush out new ideas. To be sure it is a world of difference than a training partner and having a full mat, but it does let you work subtle aspects of the arts without having to depend on a partner.
Here is a very basic introductory look to the link between Tomiki Aikido and wooden dummy work.