Nice art
I'm no pro on 2D artwork though the lighting of the cat with the blinds may have been better if the fill light was darker on the mass shadow side and if the radiosity of the figure's left matched that of the wall's reflected colours. There's be a slight diffuse transparent shadow from the arm on the tail. The reflect light on the far left edges is also slightly strong, the ear would be in more shadow too especially at the base. Try to match the light source colour, the figure light is too white and sticks out from the background. Try not to add too much detail in the darker areas as in real conditions the eyes would blur out this area when looking at the lighter areas. Try to have more contrast in your pictures if you can, it'll aid the chiaroscuro to give more punch to your images. As the light passes through the blinds it will actually reflect the sunlight and enable the eye at the light level to see some outside detail. Try studying classical art and real life to capture light better so it rings true and not slightly off a bit more. Try to dip detail in the darker regions If you are trying to create a blinding effect from the primary light source. Your fur textures are a bit muddy though if that's the style you like that is fine, though you may want to work on your specularity in terms of how much light certain texture absorbs (rough fur as opposed to smooth and reflective, etc).
I like your sketches, you are good at detail, try to consider the forms of the anatomy under the cloth as in your last picture the chest appears to dip at the shoulders, this is because the shadows in the folds are a bit too strong and the arm resting on the torso is a bit heavy and looks like its laying on a receding form and this happens at the elbow at the right, too, try to think of the masses here in terms of spherical and conal shape. Your character here is a bit rigid but I understand this pose is quite stationary, though you may benefit with better indicating the rhythm and perhaps exaggerating the composition perspective or rotation in future as your compositions are very "upright" which can be monotonous to the eye.
Your work is good, but it's worth making a note of certain basic areas so such areas don't stick out too much in time as you improve. You may also want to let your imagination fill in certain things such as textures for example on walls etc so the picture has a bit more to look at (note how the art masters in time gone by would use arrow shapes, highlights, focal points and gestures to lead the eye around the composition in a rhythmic manner) but don't over-fill, of course.
