Early morning is best -before other fishos and dogs chasing balls etc scare the fish.    Ive caught on all tides though a rising tide is best -but hard to wade if its to high!.

 Get out and wade, cover heaps of ground  look for little sand patches near weed or rocks,dropoff or anything a little different.  try a little white maribou jig (cheap and very effective)

An hour or two either side of low tide is best by far & the lower the tide the better. As anypuddle mentioned it makes the wading easier (access more ground) but I think more importantly it pushes many of the fish off the flats & over the drop offs where they will congregate until there's enough water covering the flats for them to come back up.

Lure wise I personally think soft plastics are a complete waste of time in the lower swan during the warmer months. Flathead do love them but unfortunately so do the blowies, especially in the two areas you mentioned. Not at all uncommon to lose a tail a cast so it doesn't take long to go through a few packs & have spent $30. Maribou jigs are cheap & effective as mentioned & if the blowies destroy the tail it's cheap & easy to tie on new feathers. Grab half a dozen next time your at a tackle store, they only cost $2 each. Work them in short hops like you would a vibe & you should get into some fish. Hardbody minnow style lures are by far my favourite & I find most effective to. Your scorpion 52 is a good start, others well worth having are atomic shad 40 & 50, scorpion 35, sx-40 & 48, cranka shad & the smallest laser pro. Natural colours will perform best with blues & browns being standouts. You can mix up your hardbody retrieves but usually a slow roll is all that's required to get the flatties interested.

As for area, try the flats east of point walter boat ramp rather than point walter itself. I find this area much more productive & usually there's less of the green stringy weed that can plague lure fishers.

 No need to be wading out deep either, all of the biggest flatties I've caught have been in knee deep water. Agree with cityflicker about the flats on the east side of the boatramp, always been good to me, although my biggest ever flathead came off the sand bar.

I'm a big fan of the Rio prawn lure. Been playing around with prawn star as well on my last couple of outings but have yet to catch anything on it. Scorpions also work well.

 I went down to point walter a few days ago and caught nothing. 

Buzzer and CityFlicker, which boat ramp are you guys talking about? was it the one to the right of the jetty? or further east (saw another boat ramp a few hundred meters east of the jetty).

i'm going down there again next week for another shot (might ty getting some tailor later in the afternoon too)

thanks for all the advice guys, I really appreciate it

There's only one boat ramp in that area about 250m east (right as your facing outward from the jetty), I'm not sure what second ramp your talking about. There's been some work to the foreshore down there over the last few months but as far as I'm aware there's no second ramp installed. If you take a look at google maps you will see the boat ramp, the channel heading north from the ramp & then the large section of flats we are refering to starting at the ramp & heading all the way around almost to canning bridge.