if it doesn't contribute to a "rush" item or an item you're trying to build first?
example, you kinda want a giants belt, but back wit not 1k, you buy a ruby crystal+null magic mantle or boots or cloth armor
or if say i need the 1k to complete an item, but i back with 800~, id spend the 800 on whatever items for other items ill build and wait till i come back with 1k
Sahn Uzal9 votes''Gold Tetris'' is a way of describing it that I've heard before. It's probably one of those things that you should be doing but nobody really does.
Romtheguy1 votesGold Tetris
We gotta use this phrase and make it a term!
Radiant Wukong5 votesI have a bad habit of staying in lane trying to farm another 200 gold before backing when I only have like 300 health left after winning a lane exchange then getting killed by jungle.
But I totally do the same thing you do. I normally start with 
because I spend all my gold when I recall and starting ruby crystal gives me infinite options depending on who I'm using. If I'm saving for 
(cost 700) and only have 600 gold, I'll instead buy 
and might end up getting 
or 
built before my 
which is the item I was attempting to rush.
Spending all your gold is an extremely good habit to have, especially when behind, instead of trying to save gold for a power spike.
FioraWillCarry5 votesWhen I back without enough gold to finish a big item, I just buy potions and a control ward.
For example, one that happens to me often. I have 
and 
on Kayle. I really want to get 
as soon as possible but when I backed for whatever reason, I have 800 gold which is 200 gold short of being able to get Nashor's. I just buy potions and a control ward. In a more passive lane, I'd buy 2-3 potions. In a lane where I expect to get poked a lot, I buy 5. It's a nice trade off between saving to get your powerspike sooner and coming back to lane with some kind of advantage. But don't EVER back without spending any gold at all. The only time that should happen is when you have no gold to spend at all.
Nameless Voice2 votesI have a terrible habit of buying odd items in games where I am forced to back more often than usual for whatever reason, such as building an early 
instead of the more standard 
or 
when playing Katarina, simply because its build path is so nicely filled with small, cheap items that I can buy any time I go back and don't have much gold.
Ralanr1 votesEarly game I try to be more frugal with my spending. Unless I feel I really need a big component item, I'll just buy small parts (like a cloth armor or ruby) and then grab something like boots or pots to help sustain myself in lane.
Ben Sharpio1 votesif i back with 150 gold i wait in fountain until enough gold for tier 1 boots while enemy jungler destroys all lanes and takes all of my jungle camps
Ralanr1 votesHow can you back with only 150 gold after your first clear?
A Basic Island2 votesyou back after being executed by the first buff because you forgot to buy your potions
xxxDogmanxxx1 votesDude, I main Xin Zhao. This is what my inventory looks like for most of the early game:
GULAG 4 U1 votesMeanwhile, as a yi main, I try to back with a full bF sword lol...
DarkRitual1 votesWhen I still rushed Rylai's on Morgana, I would buy Ruby Crystal or the Tome if I couldn't afford NLR. Buying components for other items instead of completing items is generally bad. Go back out, clear a few waves, ward up some and recall again to finish the item (if you aren't needed elsewhere).
RavenMagus1 votesIt's efficient to pick up extra small items especially in the early game. If you kill your opponent, go back to base to heal up after the fight, and don't spend the 300g, you have not actually gotten ahead at all. If you know you'll want an armor item later, pick up a cloth armor if your enemy laner is AD; even some extra potions and a ward will help you.
is strong and really good at expending those leftover traces of gold after a component buy. I buy it almost every game.
MunchCrunchLunch1 votesI do that early game. however when I get to late game sometiems I don't because little components mean less than a finished item that i'd have enough gold for like 2 minutes later
SmileInABox1 votesI'll save if I don't expect to be fighting particularly soon. Like if my lane is under tower and drag isn't up. Otherwise, I'll just get as many combat stats as I can.
Marshbouy1 votesWell i mean the difference between a 
+450g and can me the difference between losing or winning a jungle fight, so I always like to spend my gold on items, even if it's just 400 (unless i'm saving for an item).
(edit. Just realized that i could finish cinderhulk with that much gold XD
Not a perfect example but you get the gist)
TheHappyReaperz1 votesWhenever I'm top, and I don't want to be the first person to back, and miss out on the xp or gold, so I'll end up having 2.5k gold on my first back.
ƒoes1 votesI try to do this as well if I'm a more than 150 gold short, if not I'll just sell DBlade if I have it.
More than 200 gold short and I'll look for side items to build like Cloth Armor, Mantle, Boots, etc..
MinccinoLuna1 votesWait, doesn't everyone do this?
The thigh guy1 votesSpending all your gold ASAP is a good thing to do. Having ambient gold in your inventory does nothing for you.