Following steps we adapted while creating a practice :
1. Build a partnership/alliance with SAP on consulting/implementation and support activities.
2. Prepare a Business plan for the practice for organization approval
3. Form a small core team consisting of Architect Team preferably Business architect, SAP Technical architect, BASIS admin, Integration architect ( with RFC/Web service) and a data architect
4. suitable SAP Certifications to the team members
5. Build prototypes to showcase your competency to the prospective customers
6. Form Small presale team to pursue opportunities.
7. Recruit resources based on the project needs.
These are basic steps to start a practice.