Oh how nice!
A few things our boys FCs did do, and things I kind of wished they did:
Offering regular tea and coffee, being clear about meal expectations- should they bring food for themselves if they come over mealtimes, or will you invite them to join you? If you are going out, should they bring food for the kids? Could they bring a snack for them to divide the care or something?
Regularly popping in and out of the room to get a cup of tea, fetch bits and pieces, make a phonecall etc to give them time on their own.
Having photos of the APs in the house. Our FC sent us a picture of our son touching our pictures when he woke up in the morning and it made us feel really good when we saw it!
Being kind if its hard to do personal care for the kids- it's weird seeing a kid you barely know and having to possibly help them get dressed, wipe their bum or change nappies etc, and at 4 and 6 I should imagine they might find it trickier to accept help in more intimate matters. Narrating what you do as you help them is useful- "come on Jane, I know you normally like me to do up your zip on your jumper but not your coat, so why don't you do your jumper and I can show AP how I help you to hold the bottom. 2 hands and away the zip goes!" Etc. Or "John, I know you need help wiping your bum, so i will show mummy how we scrunch the paper, wipe and check, wipe and check until it's all clean, and then what do we do? Yes, check it's all clean with a grownup" etc. If the kids do refuse to some stuff like putting on seatbelts that you know they can do, maybe let the APs baby the kids a bit and then just mention it to them later- it allows the APs something to offer the child, and we know they they might be starting to test boundaries, but for the kids also check whether the APs know what to do to care for them.
Record yourself singing songs or saying phrases so that adoptive parents can copy you, or write them down.
Offer to take photos of the AP and children- it's their first time together as a family, and it's not like having a newborn, nobody else can really be there with them for these precious firsts, so that's a nice thing to look back on.
Take photos of brands of foods and send them to adoptive parents to stock up.
Refer to APs by the "proper" name (mum Dad mummy mama papa) even when talking to other adults whenever in earshot of the child.
Don't throw a huge goodbye party during intros. Please. It's so confusing for them!
Be clear with adoptive parents about any rules you need to follow for your agency- we panicked our son's FC because we were a bit looseygoosey with timings and got him back later than expected and she said her agency told her she needed to have him back by a certain time.
A digital drop box of any and all photos you can share.
Let the APs see you in lots of different contexts with the child - at the park, cafe, drop off at school, bedtime routines etc.
Any little details you have about BPs that you can pass on would be amazing- knowing how their final contact went was so important to us for their future care plans and understanding their behaviour. Things like knowing what songs they sang at contact, whether theynturned up on time, knowing how BPs liked the kids to wear their hair, whether they had a special toy they played with at contact, etc might have got lost with a social worker or not be in the paper work.
Don't get freaked out if APs ask about laundry powder and toothpaste brands etc- we are told to do this to ease transition, but we know its a bit weird. Maybe proffer that information and state its ok for them to ask any weird questions. Apparently it's not common knowledge that APs are asked to do that!
Check what stuff would be useful to send- our kids came with masses and masses of stuff that we only had 2 weeks of introductions to move and sort (we almost needed a truck) whilst simultaneously driving for several hours a day and working, but our house wasn't as big and it was hard to have stuff everywhere without knowing what was and wasn't emotionally significant. Our FC each gave us a single bag on the last day with medications, red books and uber important letters photos and cards from BPs that was all labelled and sorted so that we could put it somewhere safe and deal with it later. We couldn't take in any information on that day though so the labels were really helpful.
Check about gifts and contact afterwards before it all gets emotional.
Don't be surprised if contact after placement is difficult. Our boys loved their FC so much it has been really painful for them to think about them and visit them, and yet they do think and talk about them often and look at their pictures pretty much every day. Little WhatsApp videos that can be watched and rewatched were really helpful, and always end with stuff like "I know you are having a great time with your new parents and we are so happy you have found your forever family" even if you really miss them.
Fingers crossed all goes well for everybody involved!