The procedure is simple: Calculate the Greenwich Mean Time of birth and calculate the Greenwich Sidereal Time of birth.
First thing - You have to know the correct birth date-time and also place of birth. Second thing you should have a ephemeris book and a house chart. There are two types of ephemeris. One follows midnight GMT and another follows noon GMT. Here we will follow midnight GMT. Now I will describe how to make a horoscope. Read this carefully.
To work out the positions of the Ascendant, Midheaven and the house cusps, we need to know the exact Sidereal Time of birth. Now as we know the birthplace, so we know the latitude and longitude. We also know the Time Zone. For East region Time Zone is negative (-) and for West region Time Zone is positive (+).
Follow these steps:-
1)Find the GST (Greenwich sidereal time) of that day from midnight ephemeris.(you can do from noon ephemeris also but the process is different)
2)Deduct any daylight saving time from the birth time. Deduct or add the time zone, which I said earlier. Don't confuse it with Longitude. If the Time Zone is east, then subtract this from the birth time. If west, then add it.
3) With this figure, now we shall add GMT.
4) Always, Bring the figure to within 24 hours, if necessary. If you need to subtract 24 hours, then change the date to the next day. If you need to add 24 hours, then change the date to the previous day. Otherwise, you use the birth date.
5) Add the correction for GMT (10 seconds per hour of the GMT). Example, if it is 7hr then, 7hr+ (7*10) sec or (7hr + 1.17min)=7hr1.17min. We can say 7hr 1min 10sec.
6) For every degree of East longitude, we will have to add 4 minutes to the above figure. For every degree of West longitude we deduct 4minutes to the above figure. Now this is your Sidereal Time of birth.
7) Go for Table of Ascendant and other cusps chart. Find the Ascendant and other cusps according to the Sidereal Time of birth in this table. These are the some steps you have to follow. Try it.
If greater accuracy is required, we need to rectify the birth chart (we cannot rely on the accuracy of the birth time).
After finishing the calculation of house cusp, you need to find out planetary position of that day (moment) and put on birth chart. You will get these planetary positions in the Raphael’s ephemeris book.