I’ve heard people combining both Cloth and softbody for the same reason. This was for the Durian project and also called Sintel, one of Blender foundation’s open movie projects. Anyway for cloth I am more familiar with it. I recommend you look at some cloth and softbody tutorials to find what you are looking for. With cloth you need a vertex group that pins that part of the mesh from moving. So say your vertex group for cloth would be everything except for the membrane. Now the mesh can be cached but it would be wise to do this after you somewhat finalize your animation. Sometimes blender has some flaws and will tend to make the cloth behave quite bad. Either it goes into the mesh or bends oddly. So with animating be careful that you don’t have too many intersections with other meshes and it’s self. I don’t have much to say with softbody. I have not used softbody much to give any good advice.
Welcome to the forums and hope this helps some. Good luck and I hope you do well with your project :).
firstly try to “cut out” the sections of the mesh that will have the cloth sim. this will make the cloth simulation much faster.
secondly , select the verts ONLY on the edges of the “membrane” (the parts attached to the rest of the wing.) and turn them into a group… name this group “pinning” or something.
use this as the pinning group in the cloth physics panel, and ensure the pinning weight is 1.
if this is sufficient, you should be done.
However if there will be collisions between the wing and the rest of the creature… you will need to ensure the creatures mesh has correct collision settings… this will stop the flappy bit from intersecting the rest of the creatures mesh.
there are similar things to use in soft-body physics. only its refereed to as “goal group” rather than “pinning group”
and the softbody deformation works slightly differently…
after you have pinned your cloth mesh you can tweak the settings to get the right look and feel of the simulation…
try the default “leather” as a start , and adjust to your requirements.