The closest that I got to the target was 1000 exactly 😃
My strategy was to make 9 in the hundreds then 9 in the tens then use the rest for the ones because the ones will change the total the least. When you have very large numbers like 9s and 8s it is a lot harder to make 1000 because your numbers add up to totals higher than nine. When you have smaller or medium-sized numbers like 5s and 3s it is easier because it is more likely that you can make 9.
Another strategy that I used was to make 8 in the hundreds column which left me with slightly larger numbers (usually) then put the larger numbers in the tens and the rest in the ones. For both these techniques I do the ones last. This is because the ones are least significant. One time I had terrible digits (999888654) so I decided to try and get as far away from 1000 as possible. I put the nines in the hundreds, the eights in the tens, and the rest in the ones. I ended up with 1947 away.