1. Plan your trade and then trade your plan: know why you purchased the stock and if the stock is not following  your plan it is probably time to exit.
2. Why are you buying THIS stock.  Look at a chart is an entry at this point a good idea.
3. Is the stock worth buying at this price.
4. What are you buying. This is easy if your buying Google, in penny stocks its much more difficult. You must read the filings, read about the company in press releases or their website and do a search on their  CEO  or other main players using any search engine.
5. Call the transfer agent and confirm  the outstanding and authorized shares.
6. Check for dilution. This is tougher with a pink sheet stock  you can contact the state and the transfer agent. More on both dilution and e-mail to each state here.
7. Again, plan your trade and trade your plan, its easier said than done. You dont want to be riding a stock downhill.