I know this would be a question every quality tester would have in their mind. I had the same question in my mind when i started my career. I believe these points below would be helpful to you (may be).
1) Firstly you need to follow the process. If your company has a defect tracking tool, make maximum use of it. Log every single defect(even very low defect) in tracker so as to maintain a report of the defects found. Do not have any verbal communication because most of the developers will just forget about the defect or pretend to forget.
2) Make sure you have written the steps properly. When u log a defect in tracker, do read the steps twice and try analysing if the other person could understand the steps. Most developer will drop fixing few defects if they cannot analyse the steps.
3) When it comes to severity make sure it is properly marked. Some developers don't even look into low defects. If you feel that the defect needs to be fixed by next build mark it as medium.
4) This point may not be applicable to some but I feel this is the most important thing, being more friendly with your developer could lead him/her not fixing the defects. Working with developer who is a stranger is more useful than a developer who is a friend. Developer who is a friend would normally force you to forget about certain defects. So I feel bringing personal relationship to work is a strict NO NO. Have a strict work life. If you have a good friend as a developer in your project, make it clear to him that work is work, work cannot get compromised.
5) Have a chat with the developer and inform him the severity of the defect and why it needs to be fixed. But when you approach a developer make sure he/she is not in a bad mood. Always be modest by asking "Are you busy? Can I have a 10 mins chat with you about the defects"
We normally tend to forget that even developers would be busy (or they pretend to be busy) and we just start blabbering about the defect. Just imagine if someone comes up to you and informs you about how bad you look or how ugly you are, Bad isn't it :) So when you start with conversation make sure you tell these words "Can you check if this feature is working properly, I believe this sequence will crash the application. Please have a look, I will regenerate in front of you" Looks simple but very hard to execute. We normally tend to blame or put some allegation on developer as soon as we approach them
6) If your defect status is still New, make a note of those defects and call for a meeting with higher official or supervisor. Meetings and discussion solves most of the problem as developers are forced to listen to their supervisors. But when you conduct meeting make sure you have a super valid points noted down to put forward in a meeting. Normally when I feel I am losing my hold on meeting I convey this dialog " I know most of the users wouldn't perform this sequence, but 1 in 100's will surely do. You see I believe that every user is important.( Last sentence is purely fictional :P)
7) Some defects would be very hard to regenerate, Our normal tendency is to run to a developer and inform about the random crash or behavior. But as usual some developers will not give a damn to this as there is no sequence for the defect.
So i would recommend you to not rush to developer immediately. Firstly if its crashing quickly save the crash log, or if you find a glitch take a screenshot as a proof. Now try regenerating it by remembering the last 10 steps. For this you need to be 100% active while testing. If you are not able to find the sequence nth time don't lose hope. Note it down in a sticky and continue testing other features rather than sticking to 1 single defect. Finally if you cannot find it just go to developer and follow kindness behavior mentioned in point no 5 and provide maximum information about the defect and log it in tracker.
8) If its still not fixed, just send a mail to developer with cc to producers, supervisors and team member just to be in a safer side, i.e if the same defect is reported by the user, you can just forward the mail back again :P Witty isn't it :)
"A best tester is not the one who logs maximum number of defect. The best tester is one who get most of the bugs fixed"
"Every bug is reproducible, if it has occurred once"
- Bharath Shenoy
P.S
Following are the dialogs which you can use on a developer to fix defects ( make it filmy :P )
- I just conveyed this defect to the manager and he has asked you to fix this defect. (A big Lie)
- I read in one of the technical blog that an application got bad review just for not integrating this feature.
- I was telling everyone that you are a good developer and you fix all the defects.
- Don't you want your application to be a 100 % bug free. We can boast about this with other teams.
- I was telling my fellow tester that you cannot fix this defect.
- My previous developer used to fix all the defects which I reported, good na :) :)
Adios