You can manually clean up iOS to fix lag on and speed up jailbroken iPhone very effectively. These aspects can be free up: Cydia, temporary folders and system logs, and folders inside var/mobile.
Free Up Cydia space
This folder storages information files of applications installed on Cydia. Even you removed a Cydia app, there should be undeleted file such as com.app_name.plist in var/lib/dpkg/info. You can remove them. But please never modify any system files which are not in from such com.xxx.
Do not hesitate to delete all file with end of .deb because they should have been removed after the Cydia app was installed completely. They still exist there somehow, and we can totally remove all of them without any negative effects.
This is the folder for temporary keeping the packets have been added and updated source on Cydia. When you delete the source is not used, these files are stored in this more and more. Just feel free to erase the files in this directory. Some Cydia apps that after installing, they also creates temporary folder in var / root / Library / (as BatteryDoctorPro).
Clean up manually temporary folders and system logs
There is no explanation, but you can delete all data in this folder.
This is just a temporary folder of iPhone, you therefore can manually remove all data inside before the iOS automatically does.
Delete all files inside, but be noticed to keep the folder.
Clean up link directory folders of apps, Tweaks, and games downloaded on Cydia
If you uninstall any apps on Cydia, remember the app names. And then access var/mobile/Library, remove any folder which the identical name of deleted apps.
Remove all folders in var/mobile/Library/Cache, but please keep the om.apple.IconsCache folder.
This folder is where potentially keeps rubbish after removing app, tweak and game on Cydia. You will see many files in form such com.xxx.yyy.plist, delete files which include the name of removed app, game and tweak. Be noticed of that never touch any files in form of com.apple.xxx.list.
Remove all data in this folder.
Apps create un-vital data in this folder. Why don’t you remove all thing related to a particular app which had been removed?
Notification: You should have a backup solution before get my tips done if you suppose you can not follow the instruction step by step exactly.
Let do it and see how faster your iPhone will be. Cheers!