How to avoid negative slack?

[himassk]

Hi,

I am facing negative slack issue in timing analysis.

The timing analysis report is as foolows:

From: BufferFul2:CLK
To: RCounter2[8]

data required time 8.454
data arrival time 14.448
slack -5.994

Please suggest me for the following:
1. What are the methods to avoid negative slack?
2. How to reduce the delay caused by 'net'?
3. How to reduce the delay caused by 'cell'?
4. How to reduce the setup time of FF?
5. How to choose FF with fast CLK to Q delay?

Advice me about the documents/useful notes are available in net.
Thanks in advance.

Regards,
Himassk.