While not my primary photographic interest - that would be either landscape, fine art or industrial work - I do shoot a small amount of "street photography." I have yet to find a non-compliant or aggressive subject. My modus operandi? 1). I dress to blend in: blue jeans or khaki chinos with neutral colors; 2). I keep the equipment simple: an M6 with either a 35mm or 50mm lens - never anything longer; 3). If my "subject" engages in conversation, I always explain WHY I photographed her/him/them (i.e. what I found visually interesting, etc). This I do AFTER I have made my photograph(s) - I do not like posed pictures; and 4). I ALWAYS thank the party or parties involved, either with a nod of the head, a smile or a simple "thank you."
The keys, in my view: 1) Comportment; and 2) My M6s (most see these as toys and do not find them "aggressive" in the same way as SLRs and DSLRs seem to be).