I grew up in a house where me and my sister always felt the other was favoured and it was really was awful!
Now I have two children of my own I am so aware of trying not to create the same kind of atmosphere.
If my eldest child does something like make a mess by leaving his clothes on the bathroom floor I will make a point of calling him to come and clean up after himself, but I will also do the same for my youngest, despite him being 3 years younger. Any general expectations I have in terms of house jobs (taking their trays into the kitchen after dinner, getting themselves a drink, wiping the sink after brushing the teeth, emptying the lunch boxes after school etc) I will ask of both of them, not just the oldest. I don’t want to see my oldest son doing things for the youngest that I won’t do for him.
When they get home from school I give them 5-10 minutes each to tell me what they’ve done in school that day and what they’ve learnt etc and I make sure we are all in the same room as each other when we do it so they can see I’m showing them equal attention.
Same when I ask them about their sports, their friends, their homework, any other hobbies etc etc - they each get asked the same questions and they see I am equally interested in what they both want to talk about.
If we are in a room together and one comes to give me a cuddle I will give them a cuddle back and then whilst it’s still happening I will call the other over and say, “Shall we have a family cuddle?” - and then when we are all cuddling I will say “I am so lucky to have you both. I love you both so much!”
And we are in the same room together and one calls out “love you mom!” - I will call out “Love you too!!” And then I will leave it a few seconds and then call out to their child, “I love you too (child’s name).”
When I put them to bed they each get 15 minutes of 1-2-1 time with me in their room doing whatever they want (age specific) but again they see it is equal treatment rather than me spending 30 minutes with the youngest and the then just sending my eldest one upstairs on his own.
So basically, what I do with each child when it’s a 1-2-1 situation is neither here or there in relation to things like this but when we are all together as a group I ensure they receive equal amounts of positive love and attention (and they can see it’s equal) and the same expectations of their behaviour.
We also spend as much time together as we can as a family unit rather than doing separate activities which helps, but I’m lucky that the children have similar interests and each others company so it’s quite easy ti do.
Things will no doubt have to change and adapt of as they get older but for me the most important part is demonstrating to them equality in how I feel about them, my interest in them and expectations of them.