If you are considering walking this route yourself, please see my disclaimer. You may also like to see these notes about the maps and GPX files.
I stopped to eat my packed lunch on a seat on the edge of the common on my left, and then took a bridleway on the other side of the lane, which passed through a small wooded section of Hudnall Common. The bridleway then continued between a hedge on my right and the fence of a large paddock on my left. In the bottom of a small valley the bridleway turned left for a short distance, before turning right along a track to reach a stable-yard. Here arrows and waymarks pointed the way to a gate, beyond which the bridleway went down a short path and across a courtyard to reach the road through Little Gaddesden. I went a few yards left along the road and took a path on the other side, that went down a track and descended through woods, initially beside a flint wall on my left. The track turned sharply right, and continued down to the bottom of a valley (Golden Valley), a broad grassy swathe topped by woods on either side. I turned right along a track, then turned left after a hundred yards or so onto a crossing footpath. This led slightly uphill through the woods to reach a drive close to Ashridge House (I think it's a management college nowadays). I turned right, to reach a white gate and a T-junction of drives, where I turned left.
The bridleway after I turned right on Hudnall Common
The bridleway after I turned right on Hudnall Common
The bridleway continuing towards the stables at Little Gaddesden
The path down to Golden valley from Little Gaddesden
The path down to Golden valley
Golden Valley
The path just after I turned left in Golden Valley
The path after I turned left from Golden Valley, approaching Ashridge House
The path after I turned left from Golden Valley
After a few hundred yards, where the drive turned slightly left to head into more of the woods, I went straight on along a track that also entered the woods. After a few hundred yards I went left where a path crossed the track, continuing through the woods. After a while I had a huge cattle enclosure (surrounded on all sides by the woods of Ashridge) on my right (actually the public footpath goes through the end of the pasture, but there is a clear path just running through the woods next to the fence).
Ashridge House
The drive going past Ashridge House
The drive going past Ashridge House
The track into the woods
The path after I turned left
The path after I turned left
The path continuing past part of the large pasture