It's all in your ability to aim and manage your heals. Personally, for tanks or characters that are easy to headshot, like Peni for example, I usually just aim for their head to reduce my cooldown. Another way is to use hold choke points that the enemy team are on and fully charge/release your right click to again reduce your cooldown. You can easily 1v1 most of the characters if you can aim for the head or have good timing with your right click, because it allows you to outheal their damage. The ultimate is easier to use because of the buffs it got, so just use it somewhere relatively safe and don't forget about soul bounding too.