Here is an old trick used in commercial garment sewing where they do not pin or use a walking foot. Lift the leading edge of the seam you are sewing, that is the end that is going under the needle slightly off the bed of the machine. It doesn't have to be much, just a fingers width. It doesn't have to be close to the needle it can be as much as a foot away from the needle. It all depends on how long a seam you are sewing. For instance if I were sewing a long strip to another one, I would pinch the two together, lift it about a foot away from the needle and stitch until it was time to again move my fingers. For a block 9" to 12+" I would grasp the end of the seam area and lift it all until I had reached the end of where the seam goes under the needle. I usually have a finger under the fabric so as to keep the lift consistent. Now you an lift it all higher but for me a finger width is enough. It may seem cumbersome at first but will become second nature after a bit. Works great for strip piecing as well as garment sewing or top assembly. Give it a try and you may find it better than pins and such.