Constructive Advice for Building a good Relationship between sibling

Hi! We had intended to be one and done, but the universe had other plans and we’ll be welcoming a second child in August just after my daughter turns 6. My siblings were born when I was 10 and 12 and it was really not a great experience for me as a child for many reasons. We are close now, but had not effectively no relationship until they were adults. I’m wondering if people could share any constructive advice that worked well for them or in their own childhood when it comes to fostering the best possible relationship between siblings with this type of significant age gap?