I have applied some cheats on Fantasy life (RPG) on my hacked Nintendo 3DS and only play offline. I wondered if I ever decided to go online how would I avoid getting banned?

My question is a general one for all games on all systems. I know it will be individual to every game but what are the general tips? I would think changing anything in-game to be different to its normal parameters, meaning something you can't normally achieve would be a big sign-post? Like having 130 health when the max is usually 100, or unlimited special bar etc. But what about stuff like running at a faster speed (my most wanted cheat in a game usually!)

In Fantasy life in particular, I can give myself higher stats than would be possible for my current level. If I were careful to only go a little above that amount, say I gave myself 13 atk if I would only have 10 atk possible at that lvl, how likely would it be to get me caught?

IS the main threat being reported by other players who can tell? Which type of cheats/hacks would be safe? Any insight into how game moderators tend to find hackers (in all types of games) would be useful, or a link to a guide if there is one?