TextMate is great, but on more than one occasion I've come very close from going 'Office Space' on my computer when TextMate thought it would be fun to beach ball and stop responding. Over time, much thanks to my CTO, I've found some ways to make my TextMate experience faster.
PeepOpen
Pressing (Command + T) in TextMate brings up the 'Go To File' window. The suckiness of this feature is two fold. First, if you have a large project (thredUP has over 2,300 files in our project) the 'Go To File' window will hang frozen for about a year. Second, if you have multiple files similarly named then it's practically useless. Enter PeepOpen ($12).
PeepOpen is awesome for a number of reasons. For one, PeepOpen keeps a persistent index of your project files so lookup is incredibly fast. Also, through some sort of magic, you are no longer limited to just typing file names to find a file. If I were looking to load the './app/controllers/admin/users_controller.rb' file, I could type 'admin users' and the results would be dramatically narrowed. You can type any part of the path and it will match against the index.
Also try: (Command + Shift + T) brings up a window to find a method within a file. Especially handy in large models.
Project Searching
If you're searching within a file, TextMate's built-in (Command + F) is fine. If you want to search multiple files such as a folder or the entire project, don't bother pressing (Shift + Command + F). It will take forever to find anything. Luckily there are multiple free and easy to install alternatives.
The first alternative is AckMate. I think it's the most widely used search plug-in. I didn't like it. First off, it doesn't support .haml files out of the gate. So I use a much less known plug-in called NiceFind. It's simple to install (double-click the NiceFind.tmplugin file after download) and it's very fast. It also allows you to select a directory in TextMate and press (Command + Shift + T) to only recursively search in that directory.
If I'm doing a costly search such as searching through some logs, I always default to the good 'ole grep command. However, sometimes you're on the command line and outside of TextMate and you want to search for files regardless of where they are stored in your app. If that's the case, then project_search is going to be your buddy. For example, I could do 'script/find helper "def emit_"' and it knows to only search helper files for that method.
Snippets
My favorite part of TextMate. If you aren't aware of TextMate Snippets, open TextMate and go to Bundles -> Bundle Editor -> Show Bundle Editor and explore all your different options. They are broken up by file detection, which I believe is done by your bundles. So your models might be under 'Ruby' or 'Ruby on Rails' and your views might be under 'Ruby Haml' if you have a separate bundle for HAML. I could list some good ones, but this cheat sheet is all you really need.
You can also go one step further and create your own snippets. While you're in the Bundle editor, select the bundle you want to add a snippet for and then click the '+' button in the bottom left. One of the ones I made is for Haml. Very commonly there is a JavaScript file I want to include for a page that also requires a jQuery DOM Ready setup call. So I created this snippet:
For the Activation field, I selected 'Key Equivalent' and put in the three letters 'cfj'. What this means is if I'm in a Haml file and I type cfj and press the tab key (which is usually how most snippets are activated), the following code is output for me:
The $1 variable set in the snippet is a way to autocomplete portions of the text. So after you press tab, the cursor will be waiting in the open quotes on the JavaScript include tag. Whatever I type there will also go before the .setup(); function call as well.
ReMate
Lastly, if you have a really large project, ReMate (free) is a must. Have you ever selected TextMate and it just hangs there? It's probably because TextMate is refreshing the entire project tree. If you install ReMate, you can disable this feature. After you install ReMate, go to Window -> Disable Refresh on Regaining Focus. That simple. You can toggle this option if you want this on or not and if you want to manually refresh your project tree, right click in the folder pane and select 'Refresh All Projects'.
If you know of good ways to speed up (maybe speedUP?) your TextMate usage, I'd love to hear about them in the comments below.