England is in a position that is safe from most of the major powers in the beginning of the game. The one exception is France but control of the English Channel can protect against that. However, safety comes with a downside, expansion. All neutral countries that you might invade can be contested by another major country. This means that a safe alliance is crucial. Your best hope would be France, as that would allow you to get into Germany. If you added Germany to your alliance a stab would be inevitable. If you added Italy you would be less likely to have too much trouble if you got to Austria-Hungary. Another possible ally could be Russia so you would presumably have less confrontation over Scandinavia, a vital neutral area for whoever can get it. In this case you would probably have to include France, as that would give you more support in the west and north of Germany.

 

Now let's say your playing as England and you're allied with France and Italy. You should attempt to invade Russia from the north via Norway, Sweden, or St. Petersburg and Germany via Belgium, Holland, or Denmark. In this situation you shouldn't worry to much about France as they will have a lot in front of them to conquer. The one exception is that if you successfully invade St. Petersburg, Moscow, and/or Warsaw and Italy conquers Austria-Hungary then France will meet something of a dead end and have to make a choice about where it is to go from there. So as I stated earlier you need to become very powerful in the beginning of the game before you come under significant risk of invasion. So as a recap you need to worry about:

1. France in the beginning to make sure they are truly friendly
2. Russia from the north
3. France having nowhere to go but your territory.

Protect against these things in this situation and you should do well.

Now let's say you are allied with France and Russia. This leads to risk of not having much support in Germany because France could be fighting a stalemated war with Italy and Russia may end up having a prolonged war with Turkey and/or Austria-Hungary. Although it could be used to your benefit if you can get France and Russia to use a few open units to support you. Also it makes it so you don't have to share as many of neutral prospects that you and your allies have. However, all this leads to the chance of a stab into your territories which could come from France early on if they can catch Italy by surprise or if they are prepared to overwhelm Italy if need be. If Russia quickly defeated her enemies then you merely have to worry about Scandinavia but if they win after a prolonged effort then if you had managed to defeat Germany, those territories would be at risk. So in this case you would really need to watch your back but if you don't get caught up in Germany and your allies get caught up in long wars you may have a relatively easy game. If France didn't get caught up in Italy then you could still do pretty well but if you really need to try and get Russia tangled up with Turkey preferably so that you don't have to worry about Russia getting the best of Germany because of your efforts.

In conclusion, as I have stated before the best option depends on the personalities of your opponent but I think a western triple with France and Italy would be the safest and easiest way to go. Remember though, it is wise to change strategies regularly and if things appear to be unfolding in favor of the second choice run with it.