We rotate things with our lab, so usually
One 'fun' trip to the park with a ball each day (she LOVES chasing her ball but we limit to park or garden then put it away for indoors or sniffy walks as she gets a bit fixated)
One longer sniff walk, usually 3 or 4 local places during week then somewhere different to explore most weekends
Playing tug with one of her rope toys
A bit of training e.g. recall (either in garden or during a walk)
Frozen Kong with peanut butter / banana / whatever
Giant Kong (the one with the hole in that's weighted so wobbles) filled with frozen peas or sweetcorn
Selected recycling safe objects in a big tub with a few treats in too, so she has to dog through to get them (things like empty loo/kitchen roll tubes, empty plastic containers)
An old bath towel rolled up with different treats in each layer - probs our cheap equivalent of a snuffle mat but our girls LOVES it
Things like the giant Kong towel and recycling treasure hunt we only do every week or so, to keep the excitement.
She also gets plenty of playtime with other dogs as we generally see someone she knows at the park and let them have a zoom round / chase the ball together (sometimes a light wrestle depending on the dogs haha!)
Some great ideas on this thread, thanks - will definitely be adding some more to our routine!