In the top menu, click Groups > My groups > Add group. Fill in the group information. Make sure your group name is specific and concise.  Upload a logo and background image that is clear and relevant. Group members will then see the logo and main image on their profile in the Groups tab. 

Administrators or group members do not have access to edit the image and logo. They can reach out to the founder of the group.
Logos must be square, at least 80 x 80 pixels. The recommended size for the main image is 1920px x 400px. The image should be in JPG or PNG format. 

Specify whether your group will be public or private. Invite your contacts and friends to the group on the invitations tab in the group details.

There are two types of groups on

Private groups: you can join a private group by invitation only. This group is only visible to users who have already joined or been invited to it.
Public groups: All users can see this group, its content and join it.

How can I change the type of group?
Only group founders can switch between group types. Administrators or group members cannot change the group type.

Distribute roles and responsibilities
Add additional group administrators to keep the group active and beneficial for all members. It is good to have multiple group administrators because they can take care of the group in the absence of other administrators. Check the members' profiles carefully before approving.

Find out what members need
Ask your members what they want to talk about and tell them what input you expect from them. Create a schedule for content, at least for the first few weeks, to get conversations going. Thank members for their contributions with a "Like" or comment. Make sure your group is spam-free. Spam is the most common reason people leave groups. Report and remove spam as soon as you come across it or as it is reported to you.

Be polite.