Applying to the US:
I just finished my master's in mathematical finance. I want to apply for a PhD in math (but not in mathematical finance).
Can I start applying this year while studying and taking exams (GRE, subject GRE, IELTS, TOEFLS), or might my time be better spent on the latter?
I'm fluent in English, it's my only language, and I have a master's in math so I don't expect the GRE, IELTS or TOEFLS to be too difficult, but I may have to spend a lot of time studying for the Math GRE, which appears to be the equivalent of an LSAT/MCAT for master's or PhD and a bar exam/USMLE for bachelor's or master's.
What is the common practice in this matter? Do graduate school applicants first focus on studying and taking GRE, subject GRE, IELTS, TOEFLS, etc and then worry about applications after?
Suppose a graduate school applicant intends to study for one of those. On average how long does it take to study for, apply for, take one of those exams once (for the sake of example) and get the test (just one, for example) score?