For starting Spoken English classes,suggest following steps:
i.For one month, suggest thorough preparation on the subject;with good reference material,such as from British School of Languages,Centre for English Languages,Hyderabad etc.Accent in particular needs to be carefully rehearsed.
ii.Thereafter,u could place a brief Ad.offering your services,say for a small group,at home,in late evening,or holidays only batches. Initially,number of admissions and income may both be inconsequential.Once word gets around,u could land Institutional assignments also.There would be enough work,for seasoned Teachers,in this line
Spoken English institutes r spread all over; sorry to say that some of these institutes r manned by less than competent faculty,purely to fulfil business interests.
Best of luck.