This is my first article! sorry for my English, I'm non English speaker!
well I'd like to share some of the I've learned those years about photography and photoshop. Hope you find it useful!
Isolation: The best method is to use the pen tool. You can find a lot of tutorialsYou can play with lines, curves and shapes, follow up the object you want to isolate and save the path as a clipping path. I've been told that designers love to find it as extra bonus, in images.
I usually play with curves and levels in order to improve my images. If you have an image too dark you can bring more light by using the curves and levels tool
Shooting at night: it's strongly recommended to use a tripod if you shoot in bad light conditions. If you don't have or cannot use it, try to lean the camera against a stable surface.
ISO: in poor light conditions, it's recommended to up the ISO, with the disatvantage of as high ISO more noise. I use a noise killer software: Imagetomic noiseware professional, you can edit and remove the noise of your pics or part of it selection the areas you want to improve.
I'm sure the most of you will know all this, I just wanted to share my humble knowledge if a newbie in photography is reading me