I may be in the minority here, but I use comp kettlebells and do goblet squats with the handle up. Yes, it's challenging, but that's the point for what I do. I use the goblet squat for mobility (in which case a heavy weight does not matter much) and as an easy strength carry movement for the upper body. I found great transfer from the second part to everyday life when you carry heavy-ish stuff (buckets, boxes). As to tips, here is what worked for me:
1 - I touch the chest at the top, but try not to use it too much for support, as this would detract from the strength aspect of the movement. When I go down, the bell naturally exerts much less force on the chest, and eventually leaves it entirely.
2 - I use a weight that allows me to keep a somewhat neutral shoulder position. If you get too hunched up, then reduce the weight. It used to be that S&S prescribed the use of working weight for the goblet squat. I don't know if that is the case, but who cares? Use one bell down and practice good technique. You will get stronger and eventually will move up in weight.
3 - Sets of 5 are fine, but if you can only do sets of 3 at the larger weight with good technique when you increase weith, then do sets of 3. Eventually, you will get to sets of 5. As detailed below, I mostly go by feel. When the set gets too hard, I stop it.
For what it's worth, my go to squat had been for the last 3 year, up to a few months ago the goblet squat. 1 set (yes, just one) of 3-5 reps during the warmup. This was all very informal. I chose a kettlebell, depending on how I felt, and did a "reasonable" number of squats. For example, in the same week I could use 24, 32 and 40kg, depending on how I felt and do sets of 3-5. I also did 2-3 months of double kettlebell front squats twice a week once a year, but that's it ( with 24 kg in one hand, and 16 in the other). Of course, I did other things, mainly snatches and tennis, but no other squats. Doing this very easy squatting got me to being able to do easy sets of 5 with 40kg as part of my warmup. Also, during tennis season I almost stopped the squats entirely, doing them about once a week.
If you want to load the squat so that it becomes a strength exercise for the lower body, you will have eventually to find another squat. This winter I experimented with the barbell Zercher squat, and I really like it. It's much easier on the upper body because of the leverage, so you can use a heavier load. I just keep on using a similar pattern. 4-6 days a week, I do 1-2 sets of 3-5 Zercher squats as part of the warmup. All easy. It's the warmup. Also, I am rehabbing a groin injury, and it's really helping. I use 135 pounds now, so it's very light. Started at 115, so not much more than my 40kg goblets. I have no idea what my max. Maybe when my injury is fully healed, I will give a max a go, but that's not my ultimate goal. The goal is to nudge the weight up slowly. We'll see how it goes. If in a year I can do two sets of 5 with 165, 185 or maybe more as a warmup, then I got stronger. My goal is not to increase limit strength as much as possible, so this is probably not the best approach if that's what you want. However, for the investment in time (less than 30 seconds a day a few times each week with the 1 set of goblet squats), I find the returns are hard to beat. I started having trouble doing a set of 5 with 24 kg, and now sets of 5 with the 40 are easy. It took 3 years and I'm not winning any competition, but when times comes to move heavy stuff around, it's easy and I am less likely to get injured.
