Advice

In this post, there is some useful content from the Macmillan Dictionary about using the noun advice:
 
Advice is an uncountable noun, so:
- it is never used in the plural
- it never comes after an or a number
✗  Naomi Wolf gave me a good advice in her book.  
✓ Naomi Wolf gave me some good advice in her book.  
✗  They were always there to give practical advices.  
✓ They were always there to give practical advice.

Q: How can I refer to a single item of advice, rather than to advice in general?  
A: Advice is mostly used on its own or with some.  
If you’re worried about it, contact your doctor for advice.  
I think you should get some advice from a professional.

You can also say a word of advice, a piece of advice, or (informally) a bit of advice. But none of these expressions is common.

Don’t confuse advice (a noun) and advise (a verb):  
✗  I would advice you to choose this company.  
✓ I would advise you to choose this company.