For this topic of creating and sizing your resource quota, you can read this article about resource quota . It's will present you the sxquotas tool that help you create and adjust a resource quotas according to the current consumption. This tool allow you to do, for example :

echo "---create a initial resource quota"
sxquotas create myquota openshift
echo "---Adjust and add the double of capacity"
sxquotas adjust myquota 200%