Originally posted by ehrwien The best way to get reliable feedback would be to upload some pictures with intact EXIF data so we can see the parameters that were chosen when the shots were taken
What he said^, many of us are skilled at diagnosing what's wrong with images. Many of us have problems diagnosing problems form verbal descriptions. Especially with inexperienced photographers, they often have not identified the problem correctly.
There are a number of possibilities.
Motion blur caused by camera movement.
Motion blur due to subject movement due to subject movement.
Both of these can be affected by increasing the ISO and thereby the shutter speed. Although in some cases a tripod will be necessary.
Camera is front or back focusing. ( You have to learn to calibrate your lenses.)
Lens is decentered. ( One side is soft, one side isn't. There is no known solution to this problem apart from disassembly and randomly inserting shims, using trial and error.)
Also, too high an f stop can cause softness due to diffraction.
We won't know what we're looking at until we're looking at it.