Simple but the most effective advice, my opinion 
luckily there are a lot of shops build upon this platform which is both effective and efficient thus making prices go low.
I always check what discounts the local stores have before I go shopping. Sometimes some things can be bought in bulk for a long period of time instead of buying them at the regular price every week or several times a week.
That is my strategy when I wanted to get a new subscription I had to wait till the Black Friday to come and manage to sign up with a 45% discount
That is also a good idea, I’ll definitely remember that!