When Attempting Predictions
1. Natal Chart
This is again the first chart to look at, because nothing of significance will happen unless the related lesson is shown here......(The Natal Promise).
2. Progressed "day-for-a-year" Chart
We use this to identify "progressed to natal" chart aspects, because nothing of significance will happen unless the natal promise is activated by progression.
3. Transit Charts
We use these to identify "progressed to natal chart aspects" being activated by a planet transitting either the progressed or natal planet, because a significant event will not occur until the natal promise is activated by transits....Once again though, we focus initially upon slow-moving planets (to avoid information overload) and "home-in" on these events by looking at the inner planet transits only if we need to......[However, if the aim is to accurately predict what the event itself might be (rather than it's nature), homing-in will always be required...and Tertiary Charts can be useful for this too.]
4. Solar Return Charts
These are transit charts calculated for the exact time at which the Sun returns to it's natal zodiac position each year, which indicate events to be experienced between then and the next Solar Return......So, we use them as "stand-alone" charts to provide additional information about 1-3 above.......and for timing purposes, by monitoring transits to them throughout the year.
For example, the signs on the SR angles show how we shall see and be seen by others; prominent planets will indicate the nature of our focus for the year (Mercury=communications, Venus=relationships,etc); the houses point to the activities that might be to the fore and aspects provide clues about our likely behaviour.......whilst a transit to any of these will indicate when it will be particularly active.
5. Lunar Return Charts
These are used in the same way as Solar Return Charts, but are active for only four weeks; focus more upon our feelings and are best used as another timing indicator for the SR chart.
6. Other Return Charts
The specific lifetime-lesson that we are learning in relation to each planet is shown by it's sign/house/aspects in the natal chart, and it's Return Chart provides us with an opportunity to review/consolidate that learning before the planet commences it's next cycle......with the events of each cycle getting progressively harder/easier, depending upon how well we have learned our earlier lessons.
When Looking at Relationships
1. Individual Natal Charts
The first step is to look at the individual natal charts of both people, to identify the significant behavioural patterns and astrological lessons of this lifetime.
2. Synastry Chart
Step two is this comparison of natal chart to natal chart, identifying the astrologically significant contacts between the two individuals......outer to inner planet contacts indicate (karmic) lessons; inner to inner planet contacts reveal personality clashes/compatibility; outer to outer planets show generational viewpoint clashes/compatibility and the meanings of planets to chart points will vary according to which are involved.
3. Composite Charts
These show how the couple's relationship is seen by outsiders......The two-person team, rather than two separate individuals......So, we interpret this in exactly the same way as an individual natal chart, but the behavioural patterns and astrological lessons apply to the couple rather than each of them.....and end if/when the relationship ends.
4. Davison/Relationship Charts
These reveal the purpose of the relationship itself......the astrological reason/purpose for the two people being together......So again we interpret as a natal chart, but the relationship itself is the "native"......Thus, for example, the Sun placement will indicate where/how the relationship will "shine" and the MC will show how it presents itself to the world.
[Note : Because Davison Charts are based upon a time and place of birth, they can be progressed in the same way as any other natal chart......(enabling us to see how the relationship is likely to develop)......Whilst with composite charts, we must progress both individual charts separately and then create a progressed composite chart from the two progressed individual charts.]
I do not have the expertise to comment on the other charts you mention, COrnholio......and for those charts I have commented upon, others may use a different approach to mine.