Generally the nature of the solvents in terms of their polarity are taken into account. Normally we use polar, non-polar and water extract as solvents in addition to what Kirankumar has suggested

check your compound's nature that whether it is dissolve in polar or non polar and select solvent accordingly...  

hello,

    in my experience in phytochemistry use polar, non polar solvents. if you are planing to work in the new plant (phytochemically new one) start with chloroform solvent with  different concentration  (increasing polarity).

Perhaps you can use bioguided extraction (solvents with varying degrees of polarity). 

See this: 

Pieters, L., & Vlietinck, A. J. (2005). Bioguided isolation of pharmacologically active plant components, still a valuable strategy for the finding of new lead compounds?. Journal of Ethnopharmacology, 100(1), 57-60.

depending on what you want to extract, you can have different fractions in order to get rid of unwanted materials from your final extraction. In other words, you can have fractions like aqueous extract, n-hexane extract, chloroform extract, ethanolic

extract.....

if you could dry your plant then you could use supercritical carbon dioxide(SCCO2)

and gain a very concentrated essential oil from your plant without any water

If you are interested in extracting as many as possible compounds and you have no idea what type of compound is responsible for the activity, acetone is the best in our experience.  See  ELOFF, J N 1998 Which extractant should be used for the screening and isolation of antimicrobial components from plants? Journal of Ethnopharmacology 60, 1-8.

In other publications we have compared 12 different extractants.  KOTZE M and ELOFF J N 2002 Extraction of antibacterial compounds from Combretum microphyllum (Combretaceae). South African Journal of Botany 68, 62-67 

 ELOFF JN, FAMAKIN JO and KATERERE DRP [2005] Combretum woodii (Combretaceae) leaf extracts have high activity against Gram-negative and Gram-positive bacteria. African Journal of Biotechnology 4, 1161-1166

I am extracting some dried leaf samples by using soxhlet method. but my powdered samples looks clumpy, and not able to powder finely. the leaf sample is known with its fibre as well as mucilage contents. Will this affect my extraction ? is there any special method for extraction of these kind of plant materials?

SCCO2 method seems to be good for your material because of high diffusion (like gas) this help extraction from coarse particle

also the property of solvent can be modified by controlling pressure and temperature

Unfortunately we dont have facility for supercritical extraction