There is no simple answer for this as extraction and yield depends on the nature of compounds to be extracted from the plant sample. Each method has its own advantage and disadvantage and each method also needs experiment to optimise the yield of the extraction. You may start by doing a literature search to find out if there is already an established method for the plant in question or related species and compounds of interest to be extracted. You need to also consider the volume of the sample to be extracted: for example, Soxhlet can allow you to process large sample size; you can extract it exhaustively but may take few days to do so. If your compounds are heat sensitive, Soxhlet would not be the choice. For small sample size, say analytical assay, other methods such as ultrasonic extractions in addition to microwave-assisted extraction may be considered. For exceptionally high sample volume, say several kilo grams, the likes of maceration could be considered though the yield may not be optimal. For relatively non-polar samples, you may also consider supercritical CO2 extraction which is environmentally friendly. So experiment with the available methods you have access to determine the yield and also consider the polarity and nature of compounds of interest to be extracted from the plant.

I have done three different methods for obtaining essential oils from the same plant material. After GC-MS analysis was done the composition was completely different. So depending on your needs you need to chose your extraction technique. If you want to isolate a particular component do multiple test extractions and see which produces the highest amount of desired component and then do a bulk run to get a lot of extract. Then use chromatography techniques to purify one of your interest.