If you want to use formula to give yourself a break - that's fine
We all need a break at times! You could express instead if that's an option for you?
If I do want to give sleep training a concerted go (and no, I'm not *sure* there is no discomfort), how do you think I'm best to go about it? If I haven't held her until she falls asleep in my arms, she'll typically be crying a lot by the time she gets to her bed. Do I shh/pat in her bed? What if that just makes her cry more? How long do I do it for before giving up on a nap? Is there any period of crying that I can 'allow' as part of it? Once she's asleep (or appears to be), how long do I carry on shh/pat for? Sorry for all the ?s - it's just that if I'm going to do it, I need to get my info right.
I have clubs with her on Monday and Tuesday mornings (11am and 10am) - can I still sleep train with those in the diary?
Sleep training will inevitably involve some crying as LO protests the change - the goal of sleep training is not to prevent her crying, it is to give her the skills to become an independent sleeper. The important part is that you stay with her through the crying so that you maintain her trust and can comfort her through the change. It's ok to leave her if she is 'mantra crying' which is part of LO settling - but if it's a proper 'I need you' then you stay with her.
To make it as gentle as possible on you both, I would use shh-pat in your arms until she is almost asleep, then put her down in her bed and carry on shh-pat until she is asleep. Personally I would stop once she's asleep, but I think Tracy suggests doing it for a few minutes longer until LO is in a deeper sleep. Gradually over time you reduce the amount you do in your arms and do more in the crib, until all your shh-pat is in the crib. You then stop your shh-pat earlier and earlier so you pat until drowsy, then until calm but awake, then stop the shh-pat all together.
It will take time - I would try for naps for max 45 mins, then take a break, do some low-key A time and try again in an hour or so. She may skip some naps, particularly in the first few days. It is ok to do sleep training just for naps. Feeding to sleep in the evening is totally your call. If it doesn't seem to be affecting her ability to self settle at night and you both enjoy it, then stick with it.
With your clubs - I'd see if you can clear the diary for just a few days when you start out so that you have some consistency for LO to get used to the new 'system' for going to sleep. After that it won't matter quite so much if you have the odd day where naps get messed up. From my own experience though - as LO grows and A times/nap times change, it's been hard to consistently continue an activity at the same time every week and we've ended up changing things around quite a bit. That's just my way of doing it though - for me, going to a club at nap time wasn't worth it if it meant I had an overtired cranky baby the rest of the day! If your LO will nap in the car/pram you may find it a bit easier though