Your profile picture should be your logo – nothing else. And do not change this. It is your brand and needs to be recognisable and consistent.
Your cover picture / photograph is the door to your business so it needs to be of a high quality. It must not be ‘deceptive, misleading or infringe on someone else’s copyright’. It is also against Facebook policy to encourage people to upload your cover photograph to their personal timelines. Your cover is what gets fans to your Page, so make it a good one. Use it to express your brand and the ‘voice’ you have chosen for your brand. Consider having a cover photograph / picture that is about a current campaign. Changing this every now and again will keep your customers interested.
Once you have uploaded it, test it on a mobile device to see what it looks like and adjust accordingly. Click on the cover photograph to open it up and add a description of what the picture and your Page is about. Add a link to your website. This could encourage people to ‘like’ it and interact with it, which will, again, increase your reach.
Today you need to give your Facebook community social proof that you are the best. You will have customers who have emailed a compliment, or someone who has reviewed your product on your website, or who has said something nice to you personally. You might also want to ask a couple of your customers to give you a review. Check that your customers are happy for you to quote them, and then share their review on your Page. You could tag the business of the person whose review it is, or you could share their website. It is a good idea to collect all your reviews as you get them so you always have them handy to share.