Helpful tips**
Watch your replays after you finish a game and see what you did well and what you can improve.
Watch a pro player and get tips for that (IWillDominate/NB3(5) streams jungle only daily for example)
Pick the top champs for the position and 1 trick them or stick to the broken champs of the patch (Xin)
Find a duo that goes well with your position (for Jungler I recommend a Mid/top or a support that really enjoy roaming with you)
Look into Objective control (Lots of vids online for this) and understand why it's better than kills (pro games can end with a score of 1-0 in deaths) and which objective are best (Cloud drake is almost a waste of time early while Infernal is always strong) .
If you don't do these then you're not willing to improve and having someone analyze your mistakes for you wont help as much as you watching yourself and realising what went wrong. If you have questions please consider adding me and asking them.