3 month old DD (14 weeks) is generally a pretty easy baby and usually sleeps 8-6ish with one wake up, although it has been 2 a few times recently. For the first 2 months we generally kept her up until we went to bed and then I fed her to sleep, usually 9-10pm. Recently we have started a vague bedtime routine of bath, bottle, bed and she goes down around 8pm.
My question is about HOW I get her to sleep - I've been bobbing her up and down and she normally drops off in 10-15 minutes but often starts by yelling her little head off before "giving in" and dropping off on my chest. Then I gently put her in her crib (sometimes this takes 2 attempts). I really don't know how to move from this to self-settling. It's upsetting that she cries herself to sleep at the moment and also I'm knackered from what is basically an intense squat session every night 
She has never dropped off in her crib - always been put in whilst asleep, the phrase "rod for my own back" is dangling in my head 
Any advice or suggestions gratefully received! My thighs would appreciate an alternative plan...