Most of the sovereigns are pretty straight forward with their high points so I haven't specified them other than with the arrows on the images. I have mentioned for each  design some points for identifying a weak strike as opposed to wear. I hope this information helps you with your grading.

Arrows indicate the high points of Australian gold Sovereigns with the Young Head design.

For a weak strike look to the individual hair strands which will look flat but not worn (squared edges). Also the sharpness of the eye nose mouth and ear will be lacking. Look at these features in conjunction with the fields to determine a weak strike.

Arrows indicate the high points of Australian gold Sovereigns with the Sydney reverse.

A weak strike on this design shows in the fine detail of the crown which will lose definition and also along the edges of the individual leaves in the wreath, particularly the smaller leaves towards the end of the design. Keep in mind though that it is sometimes easier to see fault or weakness in a large object than in a small one. ie the larger leaves.

Arrows indicate the high points of Australian gold Sovereigns with the Shield reverse.

A weak strike is going to show all over this coin but will show first in the crown and and shield. With this design you will need to use the whole coin and pay particular attention to the obverse fields of the design to check strike quality versus wear. This coin design quite often has double grades like VF/EF of EF/aU, the reverse usually gets a higher grade because it doesn't show field wear and often appears a nicer coin. Take care and use the whole coin when grading this design.

Arrows indicate the high points of Australian gold Sovereigns with the Jubilee obverse.

Weakness will show in the last couple of pearls, the pendant, the hair, and the veil design above the forehead.
Nice big fields on this design to allow you to see the fine scratches and handling marks of a coin only lightly circulated.

Arrows indicate the high points of Australian gold Sovereigns with the Veiled Head obverse.

For a weak strike once again look to the pendant which has a large centre jewel surrounded by a number of smaller ones which will become smaller and also a flattening of the high points of the uppermost design of the crown.

Arrows indicate the high points of Australian gold Sovereigns with the Edward VII obverse.

This is a pretty soft design to start with so use of the fields is important. Whilst weakness will show in a lack of definition of the hair including beard and moustache, the easiest point to look is probably the top of the ear which should show a lack of sharpness followed by the eye.

Arrows indicate the high points of Australian gold Sovereigns with the George V obverse.

Another reasonably soft design that you need to consider the whole coin. Whilst weakness will show in a lack of definition of the hair including beard and moustache, the easiest points to look at are the top of the ear and the end of the moustache.

Arrows indicate the high points of Australian gold Sovereigns with the St George reverse.

Weakness shows in the dragon's ribs, the riders breast, the back of the sword and the riders helmet. Overall muscle definition is weaker and the cape and horses tail and eye lose sharpness and lack definition.