Well it is not that hard but one thing should be kept in mind that you should focus on small things first while making a relation special with your sibling. For example you can say simple thank you when your brother or sister is cleaning your room. Whether you are older or younger, you should compromise in some stuff to have perfect friendly relation with your siblings. Here are some important things to kept in mind.
1) They are not perfect and you are too: well you should be conscious about your sibling while keeping in mind that your siblings may not be perfect neither you. You have to make compromising decisions sometimes specially in kid’s age because sometimes things can create frustrated situations. You have to handle it with care and love.
2) Love them even if they made themselves your enemy: being siblings is beautiful. You can make your sibling best friends as well. But sometimes it might be happen that one of your sibling refuse to have healthy relation with you. This may lead an anger situation. You have to deal this situation with love and care also.
3) Watch your mouth: whether you are being teased with your teenage brother and being snapping at your toddler sister, you have to look forward the words which can get out from your mouth. Be careful while speaking even in anger mood.