3 gallon batch

I've done quite a few partial-mash 5 gallon brews so far that have turned out pretty well. There is a brew I'm interested in doing this weekend, but I think I want to do a 3 gallon batch this time. I'm kind of experimenting on this one, and I think ~30 bottles would be better than ~50 bottles. If it turns out well, I could do a full batch later.

Is there anything I need to know about doing a smaller batch? Obviously I have to adjust all the components of the recipe by 60%.

Normally I do a 3 gallon boil and then top it off to 5.25 gallons in the fermenter. Should I stick with a 3 gallon boil on this one, or take it down to ~2 gallons? If I do a 3 gallon boil, then my boil gravity will be lower, which means my hop utilization would be higher. I guess that means I should use less hops than I normally would, but I can use beercalculus or a similar resource to figure out how much I need to hit my desired IBU range.

Any other tips I might not be considering?

Use BeerSmith's scale tool. It's free to try for (I think) 21 days. You boil gravity will be MUCH higher if you don't scale your recipe down. You hop utilization is effected, but I don't know much about that. I believe BeerSmith will calculate your hops correctly though.

Something to consider, if you are using a 5 gal carboy or bucket, it is fine to do a 2.5 or 3 gallon batch and use the larger size for your PRIMARY. If you plan to move it to SECONDARY, the extra headspace on these smaller batches will serve to oxidize your beer which is a bad thing. So if considering SECONDARY, get a smaller carboy. Skipping it would be preferable.

I will be scaling my recipe down, so the OG of the wort should be similar compared to a 5 gallon batch. However, if I don't scale down the volume of the boil, then the boil gravity will be lower, and thus hop utilization would be higher. I'm not sure if it's better to do a smaller boil, or just do a 3 gallon boil and use less hops.

I'm fermenting in a 5 gallon carboy because my 6.5 gallon bucket is currently in use. That's another reason I wanted to do a 3 gallon batch, to avoid overflow. I don't plan to rack to a secondary, so I should be good there.

Go with your plan, sounds good. I misunderstood what you were talking about with a lower OG, my bad. The hop utilization is still a mystery to me, but there are plenty of threads about tweaking that on here (I'm sure).