Assign them roles and tasks
You can assign your children roles for your wedding e.g. you can make them flower girls or ring bearers if they are small. These jobs are very important and simple at the same time. Remember that you do not need to be gender-specific with this - a boy can become a flower child while a girl can be the ring bearer too. If your children are older, you can assign them the roles of bridesmaid or groomsman. You can even make your children best man or maid of honour if they desire. Besides these roles, your older children can take responsibility for important tasks like ushering and helping guests find their seats.
In the vows or ceremony
You can include your children while making vows to each other. In this scenario, children stand with the bride and groom, who then make vows to the entire family. This shows that it is not just two people who are being joined; rather, it is two families joining. You can also include your children in the Sand Mixing or Unity Candle ceremonies.
Involve the children in the wedding planning process
You can let your children help you in the wedding planning process. They can book venues by checking different marriage halls and choosing the best and most feasible one. You can also take them along for dress shopping and let them decide which outfit looks best on you. Besides this, you can let them decide which band to call for the wedding ceremony, which florist to hire and which caterers to book.
In case your children are small, they can help by choosing the fonts for the invitation cards and the design for these cards.
When given these tasks, your children will realise that they are part of the wedding ceremony, and will know that their opinion is valued.