The condition or symptoms upon which a prescription is  made are called prescribing symptoms.

1.Prescribing on constitution/general characteristics
General symptoms or the constitutional symptoms are the most valuable symptoms. Because they pertains to the patient to be cured as a whole. General characteristic symptoms consist of ;
General mental symptoms of the patient
General modalities of the patient
General physical make up of the patient

2.Prescribing on characteristics
According to Boenninghausen, the type of symptoms which constitute the totality of characteristic symptoms are;
QUIS : The make up of the patient
QUID : Peculiar sensations
UBI : Location of the disease
CUR : Cause of the disease
QUOMODO:Modalities of circumstances
QUANTO :Modality of time
QUIBUS AUXILLUS:Concomittant of symptoms
It is the qualitative totality or the characteristic symptoms to be the only one which constitute the totality of symptoms in real sense.  

3.Prescribing on causation 
*Immediate cause
Eg.Diarrhoea from milk
Constipation after coffee
*Remote cause
Trace back from Hpc or during the narration of the sufferings. Patients often say that he had never been well since that...
The cause of the disease has to be searched for, because the cause is removed, the effect go off by themselves.

4.Prescribing on suppression
If any disease condition is suppressed with allopathic medicine, or by external applications, then the prescription should be based on suppression.
Eg .Dyspnoea after suppression of skin eruption.
Rheumatism after suddenly checked diarrhoea. 

5.Prescribing on miasm
Diseases like skin eruption, syphillis or gonorrhea are normally treated by strong drugs & tropical applications. So they are driven in to the system which in turn cause miasmatic diseases. When a patient is suffering from psora, syphillis or sycosis or a combination of the two or all the three, treament is given as per miasm.

6.Prescribing on nosodes & bowel nosodes
Nosodes are medicines prepared from the diseased product of any part of the body.

Indications:
When well selected remedies fails due to interference of miasm
When well selected remedies does not hold long enough
When patient say that he has never been well since that disease. eg.Influenzinum in influenza. 
Bowel nosodes are prepared from the bacteria of the intestinal tract.
Indications: When well selected homoeopathic medicines fails due to the poisonous action of the intestinal bacteria. Bowel nosodes have the effect of cleansing the system of the poisons causing the disease.

7.Presribing on organopathic medicine
Certain medicine have the affinity to certain organs of the body. Eg.brain,heart,lungs etc..
If these organs are affected then medicines having the affinity to the corresponding diseased organ is taken from the repertory in which it is mentioned. It is  useful when there is paucity of symptoms.

8.Prescribing on laboratory investigation
In condition where there is no etiology or symptoms upon which to prescribe. Under such circumstances we have to take the help of laboratory investigations as blood, urine etc. 
Eg.Increased blood urea :Eel serum
Increased leucocytosis:Pyrogen
Pus in urine :Urine.Sediment,purulent

9.Prescribing on auto therapy & auto haemotherapy
When there is nothing to prescribe upon but the patient is suffering from some chronic disease for which no homoeopathic medicine is found then any material from the body of the patient such as stone from the kidney,sputum,blood etc. can be taken and potentised according to the homoeopathic principles and administered in different potencies.

10.Prescribing on tautopathy
This is the process of killing the bad effect caused by the modern medicine with their own medicines. The potentised form of these drugs are administered to the patient who have been harmed by the same drug in crude form.

11.Prescribing on allergy
Prescribing the potentised substance to which the patient is allergic in the crude form.
Eg.Oysters.fish etc.

12.Prescribing on the basis of placebo
Prescribe placebo in order to please the patient, to make him feel that he is taking medicine, when the action of the former dose either continues or has not taken place.
* If you are very sure of the prescription you have made, and there is no improvement in the 1st week, prescribe placebo.
* When you are very sure of the choice of medicine & the vitality of the patient is good, if there is no reason to doubt that there is something interfering with the action of medicine _ patient has to be kept on placebo until improvement taken place or new symptoms calling for a change of remedy.  

REFERENCES
Castro : Logic of repertories
Ritu : Study of repertory