Hi Tam,
You may find this of interest. It is what I call "Frames" because it frames trifecta standouts against a field of prices. I sometimes use it for my social betting at the pub on Saturday nights.

There are many frames depending on the number of runners you include in your frame and the amount of money you want to bet. Not being a real punter I use only 6 standouts for $6 at half unit bet ($3). You don't have to use a set frame but at least you know how much your ticket is going to cost.

The frames work this way. Use small fields - dogs are good. You see a set of prices, select 4 runners and then match a frame against the field of prices.

As an example of a trifecta bet take the following 4 runners which may be from a field of 8 runners -

A $1.80
B $4.30
C $6.10
D $9.70

I might use one of the following 3 Frames for my 6 standouts bet -
The 'x' denotes a selectected finishing position 1st, 2nd or 3rd.

Frame 1
1 2 3 (Position number)
A x
B x x
C x x
D x x

Frame 2
1 2 3 (Position number)
A x x
B x x
C x x
D x

Frame 3
1 2 3 (Position number)
A x x
B x x
C x x
D x

I normally have the frame patterns on a piece of paper. You still have to pick the runners of course but it is a cheaper way of doing trifectas than boxing all 4 (which is $24 for a ful bet).