Paint faces. Paint your child's face for sure, but make sure they get a chance to paint your face and / or body. It gives them a sense of creation and manipulation that helps them feel like they are able to influence you, not just be influenced. Also it's another great way to spend a lot of intentional time very close with your child. Look at their eyes while they paint you and get them to look into your eyes by asking them questions, making weird faces or just by trying to give them sloppy, painty kisses.
Give your child more control. How much control do you give them now? Can you double it? Do they get to make choices about clothing, bedtime stories, bath toys, breakfast foods, the order of chores, what room to pick up first, how long it's okay to leave toys lying around? Don't worry, being a child means being constantly reminded about who is really in charge. This is not to say that you should let your child change your mind about things, because they also need to believe that you really do have a good grasp on this life thing. Adopted children are especially susceptible to feeling a lack of control or direct responsibility for how their life is unfolding, so make sure you aren't part of that problem by building up their sense of efficacy.
Remember your goals. Is it to force them to bed at promptly 7pm or is it to make sure you continue to build your attachment? Have your priority hierarchy set up and written down. Even put it right on the fridge or somewhere your child can see it. Make sure they know that your highest priority is to be a secure family and that the other things you do are facets of this. Remind yourself of this when the times get tough and you are going to be late to work, late to school, or are just seemingly not at the same place that other parents or children are. Daily responsibilities will get you to defocus unless you find a way to continually remind yourself of these priorities.
Find ways to share something special. Your favorite ice cream flavor is now your child's. Learn to love it. Don't be completely false, but be strategic. Creating ways that you can have special similarities between you and your adopted child is a powerful way to remind them emotionally that they are part of you and they belong right where they are. Does your child come out of her room with a red sock and a black sock? Go change your socks to match if you can. Wear those socks all day and giggle to each other about it. Imagine how happy a six-year-old would be if you show up to pick them up from school wearing the same shirt as them or with a set of matching hats for you both to wear. It matters.
Adolescents and Young Adults
Continue your touch. This is why you made family hugs, holding hands, kisses, all-smashed-into-one-chair book reading, and goodnight snuggles the norm for years. Your child and your child's friends should know that you are the touchy-feely parents. Play soccer, basketball, water tag, sardines, and other physical games to keep your kid expecting your closeness and touch.
Reverse Roles. Let your child cook for you or pick your clothes out or take care of you when you are sick. Ask for hugs because you could use one. Figure out a way that your child can teach you something and ask to have them help you learn it and then ask them how you are doing later. Ask for their validation and approval sometimes.
Join with them about the things they value. Going vegan, saving water, watching videos of Minecraft, whatever it is, figure out what you can do to not just encourage them but to join with them in this meaning.
Make a big deal out of family traditions. Try to set this up earlier of course, but set your traditions and keep them. I'm not sure what direction to go on forcing children to participate, but part of the utility about it is that your child should know to rely on them regardless of whether or not they choose to participate. It could be the way you make pancakes, the way your family delegates responsibilities when you go shopping, or how you celebrate holidays.
Stop your routine to bond with your child. Children need to be reminded about what is important and even as a young adult they need to see it directly. If possible, take a day off and take your child(ren) out of school to just do something together, maybe as a response to a tough time for them or to recognize their development. Maybe it could be for no reason at all.
Be more and more honest as your child can accept it. Your child needs to know that they belong, even if the reasons for why they came to join your family were messy. Maybe a three-year-old can't fully understand choices about infertility, religion, opportunity, beliefs at the time, or even happenstance; but a fifteen-year-old chult (child/adult) can handle it and needs to understand it because if you don't share with them they will fill in the gaps with their own, possibly negative guesses.
Adult Adoptive Children.
Be honest about your failures. Maybe you should have sought to have a doctor that looked like them, or to find out more about their birth father before he died. Maybe you wish you were better at talking to their teachers while they were growing up. Don't say "I did the best I could" because that is bullshit. We do the best we do, not the best we can.
Help them with their search for meaning, belonging and fulfillment. Comparing them to others' achievement may be helpful or it may just be damaging. This is not to change expectations, but, instead to base them off of a person's own abilities and past successes. Kanye West's new album should be compared to his last albums, not what I can do with a saxophone and two hours in a studio.