I'd highly recommend their Lavender Scones and coffee and to enjoy them while sitting outside in the sunshine. You'll likely be visited by the native birds, the Superb Fairy Wren and the Firetail Finch, who will be keen to nibble on any scone scraps that you have left over. Not that you'd have much left over - the scones are pretty good,
I have been to the Lyndoch Lavender Farm 4 times in the past 12 months, and am disappointed that in 3 of the 4 visits, the customer service, both in person and on the phone, have been less than acceptable.
My big tip is: if you plan to go, make sure you ring ahead and tell them. Expect a tongue lashing mixed with a fair amount of attitude when you call, but book anyway. Turning up unannounced and expecting something as simple as a cup of coffee may result in a severe telling off from the man on the desk!