We did the walk from New Farm to Newstead House along the boardwalk. You can choose how you want to approach it. We parked in New Farm Park and walked onto the boardwalk. You could choose to park at Newstead and do it the other way round.
Whichever way, it is a very pleasant walk along the river. If you have time, pop in to see the house as it is the oldest in Brisbane and is beautifully preserved.