There is probably no sampling technique that can always be considered most appropriate. It all depends on the context, objectives and the time and budget constraints of a study.

However, random sampling is the one which is most commonly aimed by the researchers, followed by the validation of sample using known value of socio-demographic characteristics of the population obtained from Census data.

In some cases, other methods, such as stratified random sampling (in order to address specific groups), snowball sampling (to target people having knowhow of a specifc topic/subject), etc. are also considered.

All in all, the sampling method should be selected based on the circumstances of the study.

Regards

Would you elaborate more on your question, please? Generally speaking, sampling technique is determined by the choice of research approach, study design and your methods of data collection. 

There is in uniform sampling techniques for all social science research. It is largly depend on many factors including the research hypothesis/ problem, the type of the research and its objectives etc. However, it is always advisable to use random methods of sampling than non random as the random sampling gives equal opportunity for each and every unit of the sample to be part of it. Meantime, you could go for non random methods as well, when the random sampling is not possible due to various reasons.

I mean there is no uniform sampling technique