We had a great walk from Wooler Common towards Broadstruther, the smell from the heather was almost coconutty and the vivid purple went on for miles. There are well marked routes from a couple of miles to long hikes.
Forestry England have well mapped out routes on their website https://www.forestryengland.uk/wooler-common-and-woodland-park
It is essential to have your route mapped out as there are some many different routes across the common. Humleton Hill is another great walk with fantastic 360 views. https://www.northumberlandnationalpark.org.uk/walk/humbleton-hillfort/