lbb, what worked with both my older kids at that age was this;
we did the bedtime routine and tucked them up and said good night and then left the room.
they'd start to cry so we'd go back in and say 'it's time to go to sleep', kiss them and tuck them in again and leave the room, they'd scream blue murder and we'd go in every 3/4 minutes and repeat the kiss, tuck in 'goodnight sweetie' routine.
whenever they fell quiet we'd go back in and tuck them in (dd fell asleep sitting up the first two nights!).
if the woke again later in the night we'd do exactly the same rotine until they settled again
with dd it was 1.5 hours on night one with two 20 min wakings, 40 mins night two with one brief waking, 5 mins on night three with no wakings. ds1 was 50 mins night one, one brief waking during the night, 30 mins night two with no wakings and straight to sleep night 3.
dd was a chronic non-sleeper, she was actually making herself ill from lack of sleep and ds1 had gone from being quite a settled baby to refusing to go down at night at all and being chronically overtired in the daytime... for both of them i'd tried shush pat, gradual withdrawal, sitting with them for hours til they fell asleep, rewards, in fact you name it and except for just walking out and leaving them to cry like your supposed to with proper cc nothing worked, we tried each method for anywhere between 2 weeks and months so everything got it's fair shot but didn't work.
i like this method because although they scream and are very cross at you you're never completely abandoning them, you're going in and checking frequently, you're just breaking that connection between a parent being in the room and them dozing off iyswim?
both of them go down fantastically now... people are in shock if they're in my house at bedtime as one minute kids are running around, 10 mins later kids are in bed and that's the end of it... unless they're sick they go to sleep and we don't hear from them again til morning. the change in daytime behaviour after they started getting decent sleep at night was phenomonal so i have no doubt we did the rght thing, however tough it was to have to do.