Below are three separate blocks that speak practically about discipling and mutual discipleship.
In practice, how can I disciple other Christians?
Join a church.
Arrive early at church gatherings and stay late.
Practice hospitality with members of your church.
Ask God for strategic friendships.
If possible, include a line-item in your family budget for weekly time with fellow Christians. Discuss this matter with your spouse. If possible, provide such a budget line for your spouse as well.
Schedule regular breakfasts, lunches, or some other culturally-acceptable social engagement with teachable individuals (of the same sex). Depending on the person, you may decide to meet once, indefinitely, or for a set number of times (say, five). If you and the individual share a pastime, look for ways to share that pastime together.
Ask them about themselves. Ask them about their parents, spouse, children, testimony, job, walk with Christ, and so on. In asking questions, however, do so in a manner that’s appropriate for your cultural context (don’t scare them!).
Share about yourself.
Look for ways to have spiritual conversations. Maybe decide to read the Bible or some other Christian literature together.
Consider their physical or material needs. Would they benefit from your help?
Pray with them.
Depending on your home situation, invite the person to drop by your house or spend time with your family. Let them watch you live life.
What could a small group of mutual discipleship look like?
Choose 1-2 people of same gender you can trust (probably from your Community Group).
Establish an agreed upon level of confidentiality within your group.
Commit to one another.
Sync your calendars for a regular meeting time.
Begin by reading Gospel-Centered Discipleship starting with chapter 2 then coming back to chapter 1 at the end. Read a chapter then discuss.
Read through a book of the Bible together (possibly Ephesians or Colossians initially). Read portion or chapter a week then seeking to bring it to bear on your life and your partner's lives with Text-Theology-Life approach.
Agree to three rules: know your sin, fight your sin, trust your Savior.
Ask one another questions. Deep questions. Questions about the heart—unbelief,
motivations, idolatry, affections, etc.
Preach the gospel to one another.
Confess/repent, believe, worship.
Pray for one another.
Pray for Jesus to save the non-Christians in your lives you are evangelizing.
Five ways to build stronger friendships as men
Establish rhythms for your relationships.
Drop each conversation one notch deeper.
Overcome our cultural aversion to expressing affection.
Oxygenate your friendships with affirmation.
Invite friends into what you’re already doing.