Introduction
Solar Return (SR) is a chart of heavens, annual and anniversary, cast for the hour when the Sun returns to its natal position, in other words to the same degree and minute of longitude that occupied on birthday. Solar return is an additional tool which aids in determining the time when the events forecast in the nativity must be accomplished. The most important tool is, of course, the primary directions in which one degree of longitude equals one year of life. SR cannot announce events that are not indicated in the nativity. Consequently, one must not judge them alone but only in comparison with the natal chart.
Solar hour - The annual chart is not drawn for the hour of birth, it must correspond to the hour when the Sun comes back at the place which occupied in the radical theme. The reason is that SR is based on the radiant influence of the Sun on these degrees and minutes, particular to every human being. As with its annual return in Aries the Sun gives a new boost to natural forces, in the same way with its anniversary return in the personal horoscope brings an awakening of activities, energies, possibilities, important realizations in certain years , which correspond to the promises of the natal, because in those years SR and natal theme complete one another.
The pace of the Sun is not regular, the hour of regress to the same degree and minute generally varies every year, sometimes advancing, sometimes following the hour of birth. This can result in a difference of 1 degree or more between the two horoscopes. This is the reason why the solar hour must be fixed with exactitude, as it provides the right ascendant for the calculation of houses and the positions of planets.
Latitude - SR is calculated for the person's place of residence, which is not always the same with that of birth. Voyagers who, for several reasons, have no fixed home base, must establish their SR for the place where they were on their birthday. But if a person is temporarily moving, she must establish SR for her habitual residence. For example, a traveling salesman must establish SR for the city to which he returns after every trip.
On this matter other astrologers agree: C. Discepolo, T. Palamidessi, H. Gousson, A. Barbaut an A. Volguine - the father of SRs. 
Considerations
Before entering the interpretation of Solar Return, left for a later post, some considerations are necessary:
a) SRs must not be attributed primordial importance which do not posses by their own merits. Certainly, sometimes one sees SRs which, by their powerful dispositions, their excellent aspects, their actualizations, seem to bring forth these advantages. In reality, these fruitions happened because they were written in the natal theme by the primary directions of the specific year. We must bear in mind that SRs are absolutely contingent on the natal theme as far as important events of our life are concerned. Thus, we should not be astonished if trines of Sun or Moon to the Asc do not illuminate the year brightly, if a fortunate presence of a benefic in the 2nd or 7th house omits to realize either our fortune or an advantageous marriage.
b) Although dependent strictly on the radical theme, SRs posses a proper action and manifest it in the following cases:
1. They can strongly aid the evolving good influences in the radical and mitigate several flaws if they are realized in favorable conditions, or conversely, they can negate those good influences and amplify the bad if they are realized in malefic conditions against them. For a positive outcome, the planet involved should be convenient, by its essential nature and the kind of aspect it forms, to the effect foreseen or expected. If for example, Jupiter well disposed touches with conjunction, sextile, or trine the matters of money, health, honors, marriage etc, all these matters will prosper during the course of the year. But if Jupiter forms a square or opposition, these affairs will be less fortunate.
2. When in the radical theme a series of directions express an event in an imprecise interval of 2-3 years, a SR favorable to the event, can, by activating it, indicate the year and even the month when this event will take place. If on the contrary, successive SRs for 2 or 3 years are malefic and contradict the result, this will retreat to the extreme limit of its realization, as SRs have the power to advance or retard thinks according to the potential of their constituent elements.
3. SRs are above all advantageous in reminding or warning us about daily incidents. The march of the Ascendant and Sun along the zodiac, their encounters with the planets and their aspects, the placement of planets in the oriental or occidental part of the theme, all these readings give more preciseness to the forecast. Nevertheless, it is necessary to remember that the encounters which will yield the maximum of daily realization are always those which happened on birthday.
c) Although the actual state of planets (by position, aspects and domination) in the SR is accidental and does not change the significations and determinations each planet has in the natal, one must attribute to them new effects and results in relation to the SR houses they occupy or govern. A planet situated in the II radical house, can be found in the IV, VI or XII house of the SR. Thus, its effects during the year must be calculated according to the significations of the IV, VI or XII houses. But if the house, which the planet occupies in the SR, falls into the II radical house, or if, from its annual position, the planet strongly aspects the II radical, this is a certain indication that radical and annual influences will be mixed up during the year in order to produce positive or negative results, according to the houses involved.