Acer liquid mini runs on 600mhz armv6 qualcomm msm7227 cpu.this clock frequency is too slow to handle todays need.so the best way to remove the juice out of your processor is by overclocking it.
*Please note
1.Overclocking needs root,so make sure that your phone is rooted.
2.Stock kernels ie roms don't support overclocking so you will have to flash a custom kernel having overclocking ability.
3.At last you will need a overclocking software like setcpu,Android overclock etc,you can download it from googleplay or from the link below
4.Make sure you don't overclock at once like overclocking your phone from 600mhz to 787mhz,increase the frequency slightly
5.If your phone gets hanged up remove the battery and restart the phone
Download link for setcpu:http://www.mediafire.com/?d3i13faf9bgkgs2